diff --git a/Userland/Libraries/LibWeb/Bindings/AudioConstructor.cpp b/Userland/Libraries/LibWeb/Bindings/AudioConstructor.cpp
index 7ecde4ec502..b16a46ec417 100644
--- a/Userland/Libraries/LibWeb/Bindings/AudioConstructor.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/AudioConstructor.cpp
@@ -14,6 +14,8 @@
 
 namespace Web::Bindings {
 
+JS_DEFINE_ALLOCATOR(AudioConstructor);
+
 AudioConstructor::AudioConstructor(JS::Realm& realm)
     : NativeFunction(realm.intrinsics().function_prototype())
 {
diff --git a/Userland/Libraries/LibWeb/Bindings/AudioConstructor.h b/Userland/Libraries/LibWeb/Bindings/AudioConstructor.h
index 85f464da7b6..bc1f3e70b41 100644
--- a/Userland/Libraries/LibWeb/Bindings/AudioConstructor.h
+++ b/Userland/Libraries/LibWeb/Bindings/AudioConstructor.h
@@ -12,6 +12,9 @@
 namespace Web::Bindings {
 
 class AudioConstructor final : public JS::NativeFunction {
+    JS_OBJECT(AudioConstructor, JS::NativeFunction);
+    JS_DECLARE_ALLOCATOR(AudioConstructor);
+
 public:
     explicit AudioConstructor(JS::Realm&);
     virtual void initialize(JS::Realm&) override;
@@ -22,7 +25,6 @@ public:
 
 private:
     virtual bool has_constructor() const override { return true; }
-    virtual StringView class_name() const override { return "AudioConstructor"sv; }
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp
index 7250798928b..7bb9ae757a0 100644
--- a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp
@@ -14,6 +14,8 @@
 
 namespace Web::Bindings {
 
+JS_DEFINE_ALLOCATOR(ImageConstructor);
+
 ImageConstructor::ImageConstructor(JS::Realm& realm)
     : NativeFunction(realm.intrinsics().function_prototype())
 {
diff --git a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h
index a5b5f058d98..4c08de4ca5a 100644
--- a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h
+++ b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h
@@ -12,6 +12,9 @@
 namespace Web::Bindings {
 
 class ImageConstructor final : public JS::NativeFunction {
+    JS_OBJECT(ImageConstructor, JS::NativeFunction);
+    JS_DECLARE_ALLOCATOR(ImageConstructor);
+
 public:
     explicit ImageConstructor(JS::Realm&);
     virtual void initialize(JS::Realm&) override;
@@ -22,7 +25,6 @@ public:
 
 private:
     virtual bool has_constructor() const override { return true; }
-    virtual StringView class_name() const override { return "ImageConstructor"sv; }
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp b/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp
index a638213b2ea..4e19d3f8a33 100644
--- a/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp
@@ -17,6 +17,8 @@
 
 namespace Web::Bindings {
 
+JS_DEFINE_ALLOCATOR(OptionConstructor);
+
 OptionConstructor::OptionConstructor(JS::Realm& realm)
     : NativeFunction(realm.intrinsics().function_prototype())
 {
diff --git a/Userland/Libraries/LibWeb/Bindings/OptionConstructor.h b/Userland/Libraries/LibWeb/Bindings/OptionConstructor.h
index a212ddb398d..c9471e828eb 100644
--- a/Userland/Libraries/LibWeb/Bindings/OptionConstructor.h
+++ b/Userland/Libraries/LibWeb/Bindings/OptionConstructor.h
@@ -12,6 +12,9 @@
 namespace Web::Bindings {
 
 class OptionConstructor final : public JS::NativeFunction {
+    JS_OBJECT(OptionConstructor, JS::NativeFunction);
+    JS_DECLARE_ALLOCATOR(OptionConstructor);
+
 public:
     explicit OptionConstructor(JS::Realm&);
     virtual void initialize(JS::Realm&) override;
@@ -22,7 +25,6 @@ public:
 
 private:
     virtual bool has_constructor() const override { return true; }
-    virtual StringView class_name() const override { return "OptionConstructor"sv; }
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/CSS/AnimationEvent.cpp b/Userland/Libraries/LibWeb/CSS/AnimationEvent.cpp
index aeadc1b694b..83e644b62f8 100644
--- a/Userland/Libraries/LibWeb/CSS/AnimationEvent.cpp
+++ b/Userland/Libraries/LibWeb/CSS/AnimationEvent.cpp
@@ -9,6 +9,8 @@
 
 namespace Web::CSS {
 
+JS_DEFINE_ALLOCATOR(AnimationEvent);
+
 JS::NonnullGCPtr<AnimationEvent> AnimationEvent::create(JS::Realm& realm, FlyString const& type, AnimationEventInit const& event_init)
 {
     return realm.heap().allocate<AnimationEvent>(realm, realm, type, event_init);
diff --git a/Userland/Libraries/LibWeb/CSS/AnimationEvent.h b/Userland/Libraries/LibWeb/CSS/AnimationEvent.h
index d3986f2cf56..e93d4113253 100644
--- a/Userland/Libraries/LibWeb/CSS/AnimationEvent.h
+++ b/Userland/Libraries/LibWeb/CSS/AnimationEvent.h
@@ -21,6 +21,7 @@ struct AnimationEventInit : public DOM::EventInit {
 // https://www.w3.org/TR/css-animations-1/#animationevent
 class AnimationEvent : public DOM::Event {
     WEB_PLATFORM_OBJECT(AnimationEvent, DOM::Event);
+    JS_DECLARE_ALLOCATOR(AnimationEvent);
 
 public:
     [[nodiscard]] static JS::NonnullGCPtr<AnimationEvent> create(JS::Realm&, FlyString const& type, AnimationEventInit const& event_init = {});
diff --git a/Userland/Libraries/LibWeb/CSS/CSSAnimation.cpp b/Userland/Libraries/LibWeb/CSS/CSSAnimation.cpp
index f56afa98c85..1c22b5c90fa 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSAnimation.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSAnimation.cpp
@@ -11,6 +11,8 @@
 
 namespace Web::CSS {
 
+JS_DEFINE_ALLOCATOR(CSSAnimation);
+
 JS::NonnullGCPtr<CSSAnimation> CSSAnimation::create(JS::Realm& realm)
 {
     return realm.heap().allocate<CSSAnimation>(realm, realm);
diff --git a/Userland/Libraries/LibWeb/CSS/CSSAnimation.h b/Userland/Libraries/LibWeb/CSS/CSSAnimation.h
index 3ea5a993ea7..638dfef555a 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSAnimation.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSAnimation.h
@@ -15,6 +15,7 @@ namespace Web::CSS {
 // https://www.w3.org/TR/css-animations-2/#cssanimation
 class CSSAnimation : public Animations::Animation {
     WEB_PLATFORM_OBJECT(CSSAnimation, Animations::Animation);
+    JS_DECLARE_ALLOCATOR(CSSAnimation);
 
 public:
     static JS::NonnullGCPtr<CSSAnimation> create(JS::Realm&);
diff --git a/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp b/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp
index 5953dfbbbff..ef3eeb339af 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSTransition.cpp
@@ -11,6 +11,8 @@
 
 namespace Web::CSS {
 
+JS_DEFINE_ALLOCATOR(CSSTransition);
+
 JS::NonnullGCPtr<CSSTransition> CSSTransition::create(JS::Realm& realm, PropertyID property_id, size_t transition_generation)
 {
     return realm.heap().allocate<CSSTransition>(realm, realm, property_id, transition_generation);
diff --git a/Userland/Libraries/LibWeb/CSS/CSSTransition.h b/Userland/Libraries/LibWeb/CSS/CSSTransition.h
index 78557754978..1871b44f62e 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSTransition.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSTransition.h
@@ -16,6 +16,7 @@ namespace Web::CSS {
 
 class CSSTransition : public Animations::Animation {
     WEB_PLATFORM_OBJECT(CSSTransition, Animations::Animation);
+    JS_DECLARE_ALLOCATOR(CSSTransition);
 
 public:
     static JS::NonnullGCPtr<CSSTransition> create(JS::Realm&, PropertyID, size_t transition_generation);
diff --git a/Userland/Libraries/LibWeb/DOM/EventTarget.cpp b/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
index 10520ce16ab..e82471259cc 100644
--- a/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
+++ b/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
@@ -38,6 +38,8 @@
 
 namespace Web::DOM {
 
+JS_DEFINE_ALLOCATOR(EventTarget);
+
 EventTarget::EventTarget(JS::Realm& realm, MayInterfereWithIndexedPropertyAccess may_interfere_with_indexed_property_access)
     : PlatformObject(realm, may_interfere_with_indexed_property_access)
 {
diff --git a/Userland/Libraries/LibWeb/DOM/EventTarget.h b/Userland/Libraries/LibWeb/DOM/EventTarget.h
index 5ebea603b4f..4452078a716 100644
--- a/Userland/Libraries/LibWeb/DOM/EventTarget.h
+++ b/Userland/Libraries/LibWeb/DOM/EventTarget.h
@@ -19,6 +19,7 @@ namespace Web::DOM {
 
 class EventTarget : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(EventTarget, Bindings::PlatformObject);
+    JS_DECLARE_ALLOCATOR(EventTarget);
 
 public:
     virtual ~EventTarget() override;
diff --git a/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp b/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp
index 45a9e96b578..98d7f9d8471 100644
--- a/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp
+++ b/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::DOM {
 
+JS_DEFINE_ALLOCATOR(IDLEventListener);
+
 JS::NonnullGCPtr<IDLEventListener> IDLEventListener::create(JS::Realm& realm, JS::NonnullGCPtr<WebIDL::CallbackType> callback)
 {
     return realm.heap().allocate<IDLEventListener>(realm, realm, move(callback));
diff --git a/Userland/Libraries/LibWeb/DOM/IDLEventListener.h b/Userland/Libraries/LibWeb/DOM/IDLEventListener.h
index 4305919939d..60ef1defc0b 100644
--- a/Userland/Libraries/LibWeb/DOM/IDLEventListener.h
+++ b/Userland/Libraries/LibWeb/DOM/IDLEventListener.h
@@ -26,6 +26,7 @@ struct AddEventListenerOptions : public EventListenerOptions {
 
 class IDLEventListener final : public JS::Object {
     JS_OBJECT(IDLEventListener, JS::Object);
+    JS_DECLARE_ALLOCATOR(IDLEventListener);
 
 public:
     [[nodiscard]] static JS::NonnullGCPtr<IDLEventListener> create(JS::Realm&, JS::NonnullGCPtr<WebIDL::CallbackType>);
diff --git a/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp b/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp
index b1bffc92ade..57dc3076161 100644
--- a/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp
+++ b/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp
@@ -12,6 +12,7 @@
 namespace Web::DOM {
 
 JS_DEFINE_ALLOCATOR(MutationObserver);
+JS_DEFINE_ALLOCATOR(TransientRegisteredObserver);
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<MutationObserver>> MutationObserver::construct_impl(JS::Realm& realm, JS::GCPtr<WebIDL::CallbackType> callback)
 {
diff --git a/Userland/Libraries/LibWeb/DOM/MutationObserver.h b/Userland/Libraries/LibWeb/DOM/MutationObserver.h
index dae9ba3d1e4..176af145de6 100644
--- a/Userland/Libraries/LibWeb/DOM/MutationObserver.h
+++ b/Userland/Libraries/LibWeb/DOM/MutationObserver.h
@@ -93,6 +93,7 @@ private:
 // https://dom.spec.whatwg.org/#transient-registered-observer
 class TransientRegisteredObserver final : public RegisteredObserver {
     JS_CELL(TransientRegisteredObserver, RegisteredObserver);
+    JS_DECLARE_ALLOCATOR(TransientRegisteredObserver);
 
 public:
     static JS::NonnullGCPtr<TransientRegisteredObserver> create(MutationObserver&, MutationObserverInit const&, RegisteredObserver& source);
diff --git a/Userland/Libraries/LibWeb/DOM/ParentNode.cpp b/Userland/Libraries/LibWeb/DOM/ParentNode.cpp
index 7a01a9c3e15..a009ffe56dd 100644
--- a/Userland/Libraries/LibWeb/DOM/ParentNode.cpp
+++ b/Userland/Libraries/LibWeb/DOM/ParentNode.cpp
@@ -19,6 +19,8 @@
 
 namespace Web::DOM {
 
+JS_DEFINE_ALLOCATOR(ParentNode);
+
 // https://dom.spec.whatwg.org/#dom-parentnode-queryselector
 WebIDL::ExceptionOr<JS::GCPtr<Element>> ParentNode::query_selector(StringView selector_text)
 {
diff --git a/Userland/Libraries/LibWeb/DOM/ParentNode.h b/Userland/Libraries/LibWeb/DOM/ParentNode.h
index c1d8a419ab0..a84d23d07a6 100644
--- a/Userland/Libraries/LibWeb/DOM/ParentNode.h
+++ b/Userland/Libraries/LibWeb/DOM/ParentNode.h
@@ -12,6 +12,7 @@ namespace Web::DOM {
 
 class ParentNode : public Node {
     WEB_PLATFORM_OBJECT(ParentNode, Node);
+    JS_DECLARE_ALLOCATOR(ParentNode);
 
 public:
     template<typename F>
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.cpp b/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.cpp
index 562ad4ff9d3..c4e4c2eae77 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Fetch::Infrastructure {
 
+JS_DEFINE_ALLOCATOR(FetchTimingInfo);
+
 FetchTimingInfo::FetchTimingInfo() = default;
 
 JS::NonnullGCPtr<FetchTimingInfo> FetchTimingInfo::create(JS::VM& vm)
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.h b/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.h
index a1d6fff66c6..05a52d634d0 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.h
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/FetchTimingInfo.h
@@ -19,6 +19,7 @@ namespace Web::Fetch::Infrastructure {
 // https://fetch.spec.whatwg.org/#fetch-timing-info
 class FetchTimingInfo : public JS::Cell {
     JS_CELL(FetchTimingInfo, JS::Cell);
+    JS_DECLARE_ALLOCATOR(FetchTimingInfo);
 
 public:
     [[nodiscard]] static JS::NonnullGCPtr<FetchTimingInfo> create(JS::VM&);
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.cpp b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.cpp
index eff62554797..0d4c9d994ff 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.cpp
@@ -25,6 +25,8 @@
 
 namespace Web::Fetch::Infrastructure {
 
+JS_DEFINE_ALLOCATOR(HeaderList);
+
 template<typename T>
 requires(IsSameIgnoringCV<T, u8>) struct CaseInsensitiveBytesTraits : public Traits<Span<T>> {
     static constexpr bool equals(Span<T> const& a, Span<T> const& b)
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.h b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.h
index 85d98746709..4b7436c22ee 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.h
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.h
@@ -14,8 +14,8 @@
 #include <AK/String.h>
 #include <AK/Vector.h>
 #include <LibJS/Forward.h>
-#include <LibJS/Heap/Cell.h>
 #include <LibJS/Heap/GCPtr.h>
+#include <LibJS/Heap/Heap.h>
 #include <LibWeb/MimeSniff/MimeType.h>
 
 namespace Web::Fetch::Infrastructure {
@@ -35,6 +35,7 @@ class HeaderList final
     : public JS::Cell
     , Vector<Header> {
     JS_CELL(HeaderList, JS::Cell);
+    JS_DECLARE_ALLOCATOR(HeaderList);
 
 public:
     using Vector::begin;
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp
index 00b0f96b73f..2ac0c7dfa50 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp
@@ -20,6 +20,8 @@
 
 namespace Web::Geometry {
 
+JS_DEFINE_ALLOCATOR(DOMMatrixReadOnly);
+
 // https://drafts.fxtf.org/geometry/#dom-dommatrixreadonly-dommatrixreadonly
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMMatrixReadOnly>> DOMMatrixReadOnly::construct_impl(JS::Realm& realm, Optional<Variant<String, Vector<double>>> const& init)
 {
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h
index f779da523c0..f69b9850cda 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h
+++ b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h
@@ -52,6 +52,7 @@ class DOMMatrixReadOnly
     : public Bindings::PlatformObject
     , public Bindings::Serializable {
     WEB_PLATFORM_OBJECT(DOMMatrixReadOnly, Bindings::PlatformObject);
+    JS_DECLARE_ALLOCATOR(DOMMatrixReadOnly);
 
 public:
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMMatrixReadOnly>> construct_impl(JS::Realm&, Optional<Variant<String, Vector<double>>> const& init);
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.cpp b/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.cpp
index 7819878a4a4..27a8a0d4424 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.cpp
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.cpp
@@ -21,6 +21,8 @@
 
 namespace Web::HTML {
 
+JS_DEFINE_ALLOCATOR(EventLoop);
+
 EventLoop::EventLoop()
 {
     m_task_queue = heap().allocate_without_realm<TaskQueue>(*this);
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h b/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
index 4bd953bd2f9..ebb4a794cdb 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
@@ -17,6 +17,7 @@ namespace Web::HTML {
 
 class EventLoop : public JS::Cell {
     JS_CELL(EventLoop, Cell);
+    JS_DECLARE_ALLOCATOR(EventLoop);
 
 public:
     enum class Type {
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.cpp b/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.cpp
index 828105299a0..8cea970cc5f 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.cpp
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::HTML {
 
+JS_DEFINE_ALLOCATOR(TaskQueue);
+
 TaskQueue::TaskQueue(HTML::EventLoop& event_loop)
     : m_event_loop(event_loop)
 {
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h b/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h
index ba1ff5ac96e..7bf230e4102 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h
@@ -14,6 +14,7 @@ namespace Web::HTML {
 
 class TaskQueue : public JS::Cell {
     JS_CELL(TaskQueue, Cell);
+    JS_DECLARE_ALLOCATOR(TaskQueue);
 
 public:
     explicit TaskQueue(HTML::EventLoop&);
diff --git a/Userland/Libraries/LibWeb/HTML/Navigation.cpp b/Userland/Libraries/LibWeb/HTML/Navigation.cpp
index 55f11d3f07a..c8b9bdc0d26 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigation.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Navigation.cpp
@@ -31,6 +31,7 @@
 namespace Web::HTML {
 
 JS_DEFINE_ALLOCATOR(Navigation);
+JS_DEFINE_ALLOCATOR(NavigationAPIMethodTracker);
 
 static NavigationResult navigation_api_method_tracker_derived_result(JS::NonnullGCPtr<NavigationAPIMethodTracker> api_method_tracker);
 
diff --git a/Userland/Libraries/LibWeb/HTML/Navigation.h b/Userland/Libraries/LibWeb/HTML/Navigation.h
index cdef9be2a28..25319147e18 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigation.h
+++ b/Userland/Libraries/LibWeb/HTML/Navigation.h
@@ -47,6 +47,7 @@ struct NavigationResult {
 // https://html.spec.whatwg.org/multipage/nav-history-apis.html#navigation-api-method-tracker
 struct NavigationAPIMethodTracker final : public JS::Cell {
     JS_CELL(NavigationAPIMethodTracker, JS::Cell);
+    JS_DECLARE_ALLOCATOR(NavigationAPIMethodTracker);
 
     NavigationAPIMethodTracker(JS::NonnullGCPtr<Navigation> navigation,
         Optional<String> key,
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.cpp b/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.cpp
index 7b4433096f7..beefc4b3f29 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.cpp
@@ -28,6 +28,8 @@
 
 namespace Web::HTML {
 
+JS_DEFINE_ALLOCATOR(FetchContext);
+
 OnFetchScriptComplete create_on_fetch_script_complete(JS::Heap& heap, Function<void(JS::GCPtr<Script>)> function)
 {
     return JS::create_heap_function(heap, move(function));
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.h b/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.h
index 2c9b3a575cd..87694ee1038 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/Fetching.h
@@ -56,6 +56,7 @@ ScriptFetchOptions default_classic_script_fetch_options();
 
 class FetchContext : public JS::GraphLoadingState::HostDefined {
     JS_CELL(FetchContext, JS::GraphLoadingState::HostDefined);
+    JS_DECLARE_ALLOCATOR(FetchContext);
 
 public:
     JS::Value parse_error;                                    // [[ParseError]]
diff --git a/Userland/Libraries/LibWeb/Layout/AudioBox.cpp b/Userland/Libraries/LibWeb/Layout/AudioBox.cpp
index 3301345b7c4..bf662af57a4 100644
--- a/Userland/Libraries/LibWeb/Layout/AudioBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/AudioBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(AudioBox);
+
 AudioBox::AudioBox(DOM::Document& document, DOM::Element& element, NonnullRefPtr<CSS::StyleProperties> style)
     : ReplacedBox(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/AudioBox.h b/Userland/Libraries/LibWeb/Layout/AudioBox.h
index f8f62678887..326f3de34f9 100644
--- a/Userland/Libraries/LibWeb/Layout/AudioBox.h
+++ b/Userland/Libraries/LibWeb/Layout/AudioBox.h
@@ -14,6 +14,7 @@ namespace Web::Layout {
 
 class AudioBox final : public ReplacedBox {
     JS_CELL(AudioBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(AudioBox);
 
 public:
     HTML::HTMLAudioElement& dom_node();
diff --git a/Userland/Libraries/LibWeb/Layout/BreakNode.cpp b/Userland/Libraries/LibWeb/Layout/BreakNode.cpp
index cb4c9cd9e5b..d5f2dda2e0e 100644
--- a/Userland/Libraries/LibWeb/Layout/BreakNode.cpp
+++ b/Userland/Libraries/LibWeb/Layout/BreakNode.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(BreakNode);
+
 BreakNode::BreakNode(DOM::Document& document, HTML::HTMLBRElement& element, NonnullRefPtr<CSS::StyleProperties> style)
     : Layout::NodeWithStyleAndBoxModelMetrics(document, &element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/BreakNode.h b/Userland/Libraries/LibWeb/Layout/BreakNode.h
index 6e4a1063aea..57a23c1d808 100644
--- a/Userland/Libraries/LibWeb/Layout/BreakNode.h
+++ b/Userland/Libraries/LibWeb/Layout/BreakNode.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class BreakNode final : public NodeWithStyleAndBoxModelMetrics {
     JS_CELL(BreakNode, NodeWithStyleAndBoxModelMetrics);
+    JS_DECLARE_ALLOCATOR(BreakNode);
 
 public:
     BreakNode(DOM::Document&, HTML::HTMLBRElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/ButtonBox.cpp b/Userland/Libraries/LibWeb/Layout/ButtonBox.cpp
index d578ac8f1a3..4f6369d001c 100644
--- a/Userland/Libraries/LibWeb/Layout/ButtonBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/ButtonBox.cpp
@@ -11,6 +11,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(ButtonBox);
+
 ButtonBox::ButtonBox(DOM::Document& document, HTML::HTMLInputElement& element, NonnullRefPtr<CSS::StyleProperties> style)
     : FormAssociatedLabelableNode(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/ButtonBox.h b/Userland/Libraries/LibWeb/Layout/ButtonBox.h
index b8790c39f4a..de2dcaf75ad 100644
--- a/Userland/Libraries/LibWeb/Layout/ButtonBox.h
+++ b/Userland/Libraries/LibWeb/Layout/ButtonBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class ButtonBox final : public FormAssociatedLabelableNode {
     JS_CELL(ButtonBox, FormAssociatedLabelableNode);
+    JS_DECLARE_ALLOCATOR(ButtonBox);
 
 public:
     ButtonBox(DOM::Document&, HTML::HTMLInputElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/CanvasBox.cpp b/Userland/Libraries/LibWeb/Layout/CanvasBox.cpp
index df053968130..2d4c9239e1f 100644
--- a/Userland/Libraries/LibWeb/Layout/CanvasBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/CanvasBox.cpp
@@ -9,6 +9,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(CanvasBox);
+
 CanvasBox::CanvasBox(DOM::Document& document, HTML::HTMLCanvasElement& element, NonnullRefPtr<CSS::StyleProperties> style)
     : ReplacedBox(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/CanvasBox.h b/Userland/Libraries/LibWeb/Layout/CanvasBox.h
index 30ab9e581db..566a250386f 100644
--- a/Userland/Libraries/LibWeb/Layout/CanvasBox.h
+++ b/Userland/Libraries/LibWeb/Layout/CanvasBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class CanvasBox final : public ReplacedBox {
     JS_CELL(CanvasBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(CanvasBox);
 
 public:
     CanvasBox(DOM::Document&, HTML::HTMLCanvasElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/CheckBox.cpp b/Userland/Libraries/LibWeb/Layout/CheckBox.cpp
index e270d28b7fa..f7c51b36396 100644
--- a/Userland/Libraries/LibWeb/Layout/CheckBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/CheckBox.cpp
@@ -13,6 +13,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(CheckBox);
+
 CheckBox::CheckBox(DOM::Document& document, HTML::HTMLInputElement& element, NonnullRefPtr<CSS::StyleProperties> style)
     : FormAssociatedLabelableNode(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/CheckBox.h b/Userland/Libraries/LibWeb/Layout/CheckBox.h
index a7d92fd2b5b..9bc631e476e 100644
--- a/Userland/Libraries/LibWeb/Layout/CheckBox.h
+++ b/Userland/Libraries/LibWeb/Layout/CheckBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class CheckBox final : public FormAssociatedLabelableNode {
     JS_CELL(CheckBox, FormAssociatedLabelableNode);
+    JS_DECLARE_ALLOCATOR(CheckBox);
 
 public:
     CheckBox(DOM::Document&, HTML::HTMLInputElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/FrameBox.cpp b/Userland/Libraries/LibWeb/Layout/FrameBox.cpp
index abe6ed85c55..b0c1d3287bb 100644
--- a/Userland/Libraries/LibWeb/Layout/FrameBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FrameBox.cpp
@@ -11,6 +11,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(FrameBox);
+
 FrameBox::FrameBox(DOM::Document& document, DOM::Element& element, NonnullRefPtr<CSS::StyleProperties> style)
     : ReplacedBox(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/FrameBox.h b/Userland/Libraries/LibWeb/Layout/FrameBox.h
index 0dec7b0a8b6..fd694c2dea1 100644
--- a/Userland/Libraries/LibWeb/Layout/FrameBox.h
+++ b/Userland/Libraries/LibWeb/Layout/FrameBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class FrameBox final : public ReplacedBox {
     JS_CELL(FrameBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(FrameBox);
 
 public:
     FrameBox(DOM::Document&, DOM::Element&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/ImageBox.cpp b/Userland/Libraries/LibWeb/Layout/ImageBox.cpp
index b28d12b2fcb..338b8f995be 100644
--- a/Userland/Libraries/LibWeb/Layout/ImageBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/ImageBox.cpp
@@ -14,6 +14,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(ImageBox);
+
 ImageBox::ImageBox(DOM::Document& document, DOM::Element& element, NonnullRefPtr<CSS::StyleProperties> style, ImageProvider const& image_provider)
     : ReplacedBox(document, element, move(style))
     , m_image_provider(image_provider)
diff --git a/Userland/Libraries/LibWeb/Layout/ImageBox.h b/Userland/Libraries/LibWeb/Layout/ImageBox.h
index 93d91a65a20..7ae100bd752 100644
--- a/Userland/Libraries/LibWeb/Layout/ImageBox.h
+++ b/Userland/Libraries/LibWeb/Layout/ImageBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class ImageBox final : public ReplacedBox {
     JS_CELL(ImageBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(ImageBox);
 
 public:
     ImageBox(DOM::Document&, DOM::Element&, NonnullRefPtr<CSS::StyleProperties>, ImageProvider const&);
diff --git a/Userland/Libraries/LibWeb/Layout/InlineNode.cpp b/Userland/Libraries/LibWeb/Layout/InlineNode.cpp
index a630a45e269..5cde6255fd7 100644
--- a/Userland/Libraries/LibWeb/Layout/InlineNode.cpp
+++ b/Userland/Libraries/LibWeb/Layout/InlineNode.cpp
@@ -14,6 +14,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(InlineNode);
+
 InlineNode::InlineNode(DOM::Document& document, DOM::Element* element, NonnullRefPtr<CSS::StyleProperties> style)
     : Layout::NodeWithStyleAndBoxModelMetrics(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/InlineNode.h b/Userland/Libraries/LibWeb/Layout/InlineNode.h
index ce067ce7613..4e21ab82870 100644
--- a/Userland/Libraries/LibWeb/Layout/InlineNode.h
+++ b/Userland/Libraries/LibWeb/Layout/InlineNode.h
@@ -12,6 +12,7 @@ namespace Web::Layout {
 
 class InlineNode final : public NodeWithStyleAndBoxModelMetrics {
     JS_CELL(InlineNode, NodeWithStyleAndBoxModelMetrics);
+    JS_DECLARE_ALLOCATOR(InlineNode);
 
 public:
     InlineNode(DOM::Document&, DOM::Element*, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/Label.cpp b/Userland/Libraries/LibWeb/Layout/Label.cpp
index 78f94ae14e4..533506a9804 100644
--- a/Userland/Libraries/LibWeb/Layout/Label.cpp
+++ b/Userland/Libraries/LibWeb/Layout/Label.cpp
@@ -15,6 +15,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(Label);
+
 Label::Label(DOM::Document& document, HTML::HTMLLabelElement* element, NonnullRefPtr<CSS::StyleProperties> style)
     : BlockContainer(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/Label.h b/Userland/Libraries/LibWeb/Layout/Label.h
index d17b6422038..e11a07fcc52 100644
--- a/Userland/Libraries/LibWeb/Layout/Label.h
+++ b/Userland/Libraries/LibWeb/Layout/Label.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class Label final : public BlockContainer {
     JS_CELL(Label, BlockContainer);
+    JS_DECLARE_ALLOCATOR(Label);
 
 public:
     Label(DOM::Document&, HTML::HTMLLabelElement*, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/ListItemBox.cpp b/Userland/Libraries/LibWeb/Layout/ListItemBox.cpp
index 29f70350396..0dfa499f1e7 100644
--- a/Userland/Libraries/LibWeb/Layout/ListItemBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/ListItemBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(ListItemBox);
+
 ListItemBox::ListItemBox(DOM::Document& document, DOM::Element* element, NonnullRefPtr<CSS::StyleProperties> style)
     : Layout::BlockContainer(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/ListItemBox.h b/Userland/Libraries/LibWeb/Layout/ListItemBox.h
index 7f4598b398a..c05f2c88126 100644
--- a/Userland/Libraries/LibWeb/Layout/ListItemBox.h
+++ b/Userland/Libraries/LibWeb/Layout/ListItemBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class ListItemBox final : public BlockContainer {
     JS_CELL(ListItemBox, BlockContainer);
+    JS_DECLARE_ALLOCATOR(ListItemBox);
 
 public:
     ListItemBox(DOM::Document&, DOM::Element*, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.cpp b/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.cpp
index a7686dd461b..ea11ffe032d 100644
--- a/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(ListItemMarkerBox);
+
 ListItemMarkerBox::ListItemMarkerBox(DOM::Document& document, CSS::ListStyleType style_type, CSS::ListStylePosition style_position, size_t index, NonnullRefPtr<CSS::StyleProperties> style)
     : Box(document, nullptr, move(style))
     , m_list_style_type(style_type)
diff --git a/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.h b/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.h
index aa72b0ead05..66f730fb691 100644
--- a/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.h
+++ b/Userland/Libraries/LibWeb/Layout/ListItemMarkerBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class ListItemMarkerBox final : public Box {
     JS_CELL(ListItemMarkerBox, Box);
+    JS_DECLARE_ALLOCATOR(ListItemMarkerBox);
 
 public:
     explicit ListItemMarkerBox(DOM::Document&, CSS::ListStyleType, CSS::ListStylePosition, size_t index, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/RadioButton.cpp b/Userland/Libraries/LibWeb/Layout/RadioButton.cpp
index 7ec815b0365..362a3bb50ab 100644
--- a/Userland/Libraries/LibWeb/Layout/RadioButton.cpp
+++ b/Userland/Libraries/LibWeb/Layout/RadioButton.cpp
@@ -11,6 +11,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(RadioButton);
+
 RadioButton::RadioButton(DOM::Document& document, HTML::HTMLInputElement& element, NonnullRefPtr<CSS::StyleProperties> style)
     : FormAssociatedLabelableNode(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/RadioButton.h b/Userland/Libraries/LibWeb/Layout/RadioButton.h
index 6bbb135bb95..9fc315169cb 100644
--- a/Userland/Libraries/LibWeb/Layout/RadioButton.h
+++ b/Userland/Libraries/LibWeb/Layout/RadioButton.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class RadioButton final : public FormAssociatedLabelableNode {
     JS_CELL(RadioButton, FormAssociatedLabelableNode);
+    JS_DECLARE_ALLOCATOR(RadioButton);
 
 public:
     RadioButton(DOM::Document&, HTML::HTMLInputElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/SVGClipBox.cpp b/Userland/Libraries/LibWeb/Layout/SVGClipBox.cpp
index 9e961e9d9e3..4a1c8968446 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGClipBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/SVGClipBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(SVGClipBox);
+
 SVGClipBox::SVGClipBox(DOM::Document& document, SVG::SVGClipPathElement& element, NonnullRefPtr<CSS::StyleProperties> properties)
     : SVGBox(document, element, properties)
 {
diff --git a/Userland/Libraries/LibWeb/Layout/SVGClipBox.h b/Userland/Libraries/LibWeb/Layout/SVGClipBox.h
index 95bfc216e6c..db7d20a0f8c 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGClipBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGClipBox.h
@@ -14,6 +14,7 @@ namespace Web::Layout {
 
 class SVGClipBox : public SVGBox {
     JS_CELL(SVGClipBox, SVGBox);
+    JS_DECLARE_ALLOCATOR(SVGClipBox);
 
 public:
     SVGClipBox(DOM::Document&, SVG::SVGClipPathElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.cpp b/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.cpp
index 88b8212787b..c745c5ead20 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.cpp
@@ -12,6 +12,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(SVGGeometryBox);
+
 SVGGeometryBox::SVGGeometryBox(DOM::Document& document, SVG::SVGGeometryElement& element, NonnullRefPtr<CSS::StyleProperties> properties)
     : SVGGraphicsBox(document, element, properties)
 {
diff --git a/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.h b/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.h
index 9e198f319ec..c4ce6c63c9c 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGGeometryBox.h
@@ -14,6 +14,7 @@ namespace Web::Layout {
 
 class SVGGeometryBox final : public SVGGraphicsBox {
     JS_CELL(SVGGeometryBox, SVGGraphicsBox);
+    JS_DECLARE_ALLOCATOR(SVGGeometryBox);
 
 public:
     SVGGeometryBox(DOM::Document&, SVG::SVGGeometryElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/SVGMaskBox.cpp b/Userland/Libraries/LibWeb/Layout/SVGMaskBox.cpp
index c76c1c57d78..7d6f9bcc147 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGMaskBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/SVGMaskBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(SVGMaskBox);
+
 SVGMaskBox::SVGMaskBox(DOM::Document& document, SVG::SVGMaskElement& element, NonnullRefPtr<CSS::StyleProperties> properties)
     : SVGGraphicsBox(document, element, properties)
 {
diff --git a/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h b/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h
index f73fccd1cf4..d925f8815d0 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h
@@ -14,6 +14,7 @@ namespace Web::Layout {
 
 class SVGMaskBox : public SVGGraphicsBox {
     JS_CELL(SVGMaskBox, SVGBox);
+    JS_DECLARE_ALLOCATOR(SVGMaskBox);
 
 public:
     SVGMaskBox(DOM::Document&, SVG::SVGMaskElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/SVGSVGBox.cpp b/Userland/Libraries/LibWeb/Layout/SVGSVGBox.cpp
index eb06ffc8e15..a23435fbad3 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGSVGBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/SVGSVGBox.cpp
@@ -12,6 +12,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(SVGSVGBox);
+
 SVGSVGBox::SVGSVGBox(DOM::Document& document, SVG::SVGSVGElement& element, NonnullRefPtr<CSS::StyleProperties> properties)
     : ReplacedBox(document, element, move(properties))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h b/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h
index ae57bb49801..b52a9d81442 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class SVGSVGBox final : public ReplacedBox {
     JS_CELL(SVGSVGBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(SVGSVGBox);
 
 public:
     SVGSVGBox(DOM::Document&, SVG::SVGSVGElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/SVGTextBox.cpp b/Userland/Libraries/LibWeb/Layout/SVGTextBox.cpp
index a9c2bc1af5d..50d9f89a819 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGTextBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/SVGTextBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(SVGTextBox);
+
 SVGTextBox::SVGTextBox(DOM::Document& document, SVG::SVGTextPositioningElement& element, NonnullRefPtr<CSS::StyleProperties> properties)
     : SVGGraphicsBox(document, element, properties)
 {
diff --git a/Userland/Libraries/LibWeb/Layout/SVGTextBox.h b/Userland/Libraries/LibWeb/Layout/SVGTextBox.h
index 893b96d1e4b..104250daba0 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGTextBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGTextBox.h
@@ -14,6 +14,7 @@ namespace Web::Layout {
 
 class SVGTextBox final : public SVGGraphicsBox {
     JS_CELL(SVGTextBox, SVGGraphicsBox);
+    JS_DECLARE_ALLOCATOR(SVGTextBox);
 
 public:
     SVGTextBox(DOM::Document&, SVG::SVGTextPositioningElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.cpp b/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.cpp
index 27a096d16a8..58aace23302 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.cpp
@@ -9,6 +9,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(SVGTextPathBox);
+
 SVGTextPathBox::SVGTextPathBox(DOM::Document& document, SVG::SVGTextPathElement& element, NonnullRefPtr<CSS::StyleProperties> properties)
     : SVGGraphicsBox(document, element, properties)
 {
diff --git a/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.h b/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.h
index b7097d19d80..4f0a0a76616 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGTextPathBox.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class SVGTextPathBox final : public SVGGraphicsBox {
     JS_CELL(SVGTextPathBox, SVGGraphicsBox);
+    JS_DECLARE_ALLOCATOR(SVGTextPathBox);
 
 public:
     SVGTextPathBox(DOM::Document&, SVG::SVGTextPathElement&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/TableWrapper.cpp b/Userland/Libraries/LibWeb/Layout/TableWrapper.cpp
index 8323226cfa4..bdc3bf482ba 100644
--- a/Userland/Libraries/LibWeb/Layout/TableWrapper.cpp
+++ b/Userland/Libraries/LibWeb/Layout/TableWrapper.cpp
@@ -8,6 +8,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(TableWrapper);
+
 TableWrapper::TableWrapper(DOM::Document& document, DOM::Node* node, NonnullRefPtr<CSS::StyleProperties> style)
     : BlockContainer(document, node, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/TableWrapper.h b/Userland/Libraries/LibWeb/Layout/TableWrapper.h
index faa26b8e9f1..2cbb3416260 100644
--- a/Userland/Libraries/LibWeb/Layout/TableWrapper.h
+++ b/Userland/Libraries/LibWeb/Layout/TableWrapper.h
@@ -12,6 +12,7 @@ namespace Web::Layout {
 
 class TableWrapper : public BlockContainer {
     JS_CELL(TableWrapper, BlockContainer);
+    JS_DECLARE_ALLOCATOR(TableWrapper);
 
 public:
     TableWrapper(DOM::Document&, DOM::Node*, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Layout/TextNode.cpp b/Userland/Libraries/LibWeb/Layout/TextNode.cpp
index 876ecebb6ed..ccba8e6e5c8 100644
--- a/Userland/Libraries/LibWeb/Layout/TextNode.cpp
+++ b/Userland/Libraries/LibWeb/Layout/TextNode.cpp
@@ -16,6 +16,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(TextNode);
+
 TextNode::TextNode(DOM::Document& document, DOM::Text& text)
     : Node(document, &text)
 {
diff --git a/Userland/Libraries/LibWeb/Layout/TextNode.h b/Userland/Libraries/LibWeb/Layout/TextNode.h
index 0daeb1272e8..6662f9184a3 100644
--- a/Userland/Libraries/LibWeb/Layout/TextNode.h
+++ b/Userland/Libraries/LibWeb/Layout/TextNode.h
@@ -16,6 +16,7 @@ class LineBoxFragment;
 
 class TextNode final : public Node {
     JS_CELL(TextNode, Node);
+    JS_DECLARE_ALLOCATOR(TextNode);
 
 public:
     TextNode(DOM::Document&, DOM::Text&);
diff --git a/Userland/Libraries/LibWeb/Layout/VideoBox.cpp b/Userland/Libraries/LibWeb/Layout/VideoBox.cpp
index 23c8dfa01de..548dca736aa 100644
--- a/Userland/Libraries/LibWeb/Layout/VideoBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/VideoBox.cpp
@@ -10,6 +10,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(VideoBox);
+
 VideoBox::VideoBox(DOM::Document& document, DOM::Element& element, NonnullRefPtr<CSS::StyleProperties> style)
     : ReplacedBox(document, element, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/VideoBox.h b/Userland/Libraries/LibWeb/Layout/VideoBox.h
index d9ce706714f..03490c04cad 100644
--- a/Userland/Libraries/LibWeb/Layout/VideoBox.h
+++ b/Userland/Libraries/LibWeb/Layout/VideoBox.h
@@ -16,6 +16,7 @@ class VideoBox final
     : public ReplacedBox
     , public DOM::Document::ViewportClient {
     JS_CELL(VideoBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(VideoBox);
 
 public:
     virtual void prepare_for_replaced_layout() override;
diff --git a/Userland/Libraries/LibWeb/Layout/Viewport.cpp b/Userland/Libraries/LibWeb/Layout/Viewport.cpp
index 3825840b046..81d97906c2e 100644
--- a/Userland/Libraries/LibWeb/Layout/Viewport.cpp
+++ b/Userland/Libraries/LibWeb/Layout/Viewport.cpp
@@ -13,6 +13,8 @@
 
 namespace Web::Layout {
 
+JS_DEFINE_ALLOCATOR(Viewport);
+
 Viewport::Viewport(DOM::Document& document, NonnullRefPtr<CSS::StyleProperties> style)
     : BlockContainer(document, &document, move(style))
 {
diff --git a/Userland/Libraries/LibWeb/Layout/Viewport.h b/Userland/Libraries/LibWeb/Layout/Viewport.h
index dc235d3d3a1..0280ba1a4d7 100644
--- a/Userland/Libraries/LibWeb/Layout/Viewport.h
+++ b/Userland/Libraries/LibWeb/Layout/Viewport.h
@@ -13,6 +13,7 @@ namespace Web::Layout {
 
 class Viewport final : public BlockContainer {
     JS_CELL(Viewport, BlockContainer);
+    JS_DECLARE_ALLOCATOR(Viewport);
 
 public:
     explicit Viewport(DOM::Document&, NonnullRefPtr<CSS::StyleProperties>);
diff --git a/Userland/Libraries/LibWeb/Page/Page.cpp b/Userland/Libraries/LibWeb/Page/Page.cpp
index 13710cd4dfe..20af66847dc 100644
--- a/Userland/Libraries/LibWeb/Page/Page.cpp
+++ b/Userland/Libraries/LibWeb/Page/Page.cpp
@@ -25,6 +25,8 @@
 
 namespace Web {
 
+JS_DEFINE_ALLOCATOR(Page);
+
 JS::NonnullGCPtr<Page> Page::create(JS::VM& vm, JS::NonnullGCPtr<PageClient> page_client)
 {
     return vm.heap().allocate_without_realm<Page>(page_client);
diff --git a/Userland/Libraries/LibWeb/Page/Page.h b/Userland/Libraries/LibWeb/Page/Page.h
index 6450a240684..0e337e661bb 100644
--- a/Userland/Libraries/LibWeb/Page/Page.h
+++ b/Userland/Libraries/LibWeb/Page/Page.h
@@ -22,8 +22,8 @@
 #include <LibGfx/Size.h>
 #include <LibGfx/StandardCursor.h>
 #include <LibIPC/Forward.h>
-#include <LibJS/Heap/Cell.h>
 #include <LibJS/Heap/Handle.h>
+#include <LibJS/Heap/Heap.h>
 #include <LibURL/URL.h>
 #include <LibWeb/CSS/PreferredColorScheme.h>
 #include <LibWeb/CSS/Selector.h>
@@ -47,6 +47,7 @@ class PageClient;
 
 class Page final : public JS::Cell {
     JS_CELL(Page, JS::Cell);
+    JS_DECLARE_ALLOCATOR(Page);
 
 public:
     static JS::NonnullGCPtr<Page> create(JS::VM&, JS::NonnullGCPtr<PageClient>);
diff --git a/Userland/Libraries/LibWeb/Painting/AudioPaintable.cpp b/Userland/Libraries/LibWeb/Painting/AudioPaintable.cpp
index 338bb61e1d9..9ae335b779d 100644
--- a/Userland/Libraries/LibWeb/Painting/AudioPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/AudioPaintable.cpp
@@ -18,6 +18,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(AudioPaintable);
+
 JS::NonnullGCPtr<AudioPaintable> AudioPaintable::create(Layout::AudioBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<AudioPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/AudioPaintable.h b/Userland/Libraries/LibWeb/Painting/AudioPaintable.h
index 5e95e26ce8d..e82dc356c21 100644
--- a/Userland/Libraries/LibWeb/Painting/AudioPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/AudioPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class AudioPaintable final : public MediaPaintable {
     JS_CELL(AudioPaintable, MediaPaintable);
+    JS_DECLARE_ALLOCATOR(AudioPaintable);
 
 public:
     static JS::NonnullGCPtr<AudioPaintable> create(Layout::AudioBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/ButtonPaintable.cpp b/Userland/Libraries/LibWeb/Painting/ButtonPaintable.cpp
index fd0744d1c0c..71b12a459a3 100644
--- a/Userland/Libraries/LibWeb/Painting/ButtonPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/ButtonPaintable.cpp
@@ -13,6 +13,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(ButtonPaintable);
+
 JS::NonnullGCPtr<ButtonPaintable> ButtonPaintable::create(Layout::ButtonBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<ButtonPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/ButtonPaintable.h b/Userland/Libraries/LibWeb/Painting/ButtonPaintable.h
index ea974b37903..4fa9f39404d 100644
--- a/Userland/Libraries/LibWeb/Painting/ButtonPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/ButtonPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class ButtonPaintable final : public LabelablePaintable {
     JS_CELL(ButtonPaintable, LabelablePaintable);
+    JS_DECLARE_ALLOCATOR(ButtonPaintable);
 
 public:
     static JS::NonnullGCPtr<ButtonPaintable> create(Layout::ButtonBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/CanvasPaintable.cpp b/Userland/Libraries/LibWeb/Painting/CanvasPaintable.cpp
index 94d68f1ea40..92f15298e6d 100644
--- a/Userland/Libraries/LibWeb/Painting/CanvasPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/CanvasPaintable.cpp
@@ -8,6 +8,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(CanvasPaintable);
+
 JS::NonnullGCPtr<CanvasPaintable> CanvasPaintable::create(Layout::CanvasBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<CanvasPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/CanvasPaintable.h b/Userland/Libraries/LibWeb/Painting/CanvasPaintable.h
index 6a867e5c78d..0af1db04013 100644
--- a/Userland/Libraries/LibWeb/Painting/CanvasPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/CanvasPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class CanvasPaintable final : public PaintableBox {
     JS_CELL(CanvasPaintable, PaintableBox);
+    JS_DECLARE_ALLOCATOR(CanvasPaintable);
 
 public:
     static JS::NonnullGCPtr<CanvasPaintable> create(Layout::CanvasBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.cpp b/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.cpp
index ba22483be45..2cc8d66e664 100644
--- a/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.cpp
@@ -18,6 +18,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(CheckBoxPaintable);
+
 // A 16x16 signed distance field for the checkbox's tick (slightly rounded):
 static constexpr Array<u8, 16 * 16> s_check_mark_sdf {
     254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 251, 254, 254, 254,
diff --git a/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.h b/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.h
index 0b9d85cd08a..3b0cd1b055e 100644
--- a/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/CheckBoxPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class CheckBoxPaintable final : public LabelablePaintable {
     JS_CELL(CheckBoxPaintable, LabelablePaintable);
+    JS_DECLARE_ALLOCATOR(CheckBoxPaintable);
 
 public:
     static JS::NonnullGCPtr<CheckBoxPaintable> create(Layout::CheckBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/ImagePaintable.cpp b/Userland/Libraries/LibWeb/Painting/ImagePaintable.cpp
index cff8897c9dc..1fd5ac5d1a3 100644
--- a/Userland/Libraries/LibWeb/Painting/ImagePaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/ImagePaintable.cpp
@@ -18,6 +18,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(ImagePaintable);
+
 JS::NonnullGCPtr<ImagePaintable> ImagePaintable::create(Layout::ImageBox const& layout_box)
 {
     auto alt = layout_box.dom_node().get_attribute_value(HTML::AttributeNames::alt);
diff --git a/Userland/Libraries/LibWeb/Painting/ImagePaintable.h b/Userland/Libraries/LibWeb/Painting/ImagePaintable.h
index 5dc12a1da86..5eb6929293b 100644
--- a/Userland/Libraries/LibWeb/Painting/ImagePaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/ImagePaintable.h
@@ -15,6 +15,7 @@ class ImagePaintable final
     : public PaintableBox
     , public DOM::Document::ViewportClient {
     JS_CELL(ImagePaintable, PaintableBox);
+    JS_DECLARE_ALLOCATOR(ImagePaintable);
 
 public:
     static JS::NonnullGCPtr<ImagePaintable> create(Layout::ImageBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/InlinePaintable.cpp b/Userland/Libraries/LibWeb/Painting/InlinePaintable.cpp
index ae3c3114b05..f8cb065eb05 100644
--- a/Userland/Libraries/LibWeb/Painting/InlinePaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/InlinePaintable.cpp
@@ -13,6 +13,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(InlinePaintable);
+
 JS::NonnullGCPtr<InlinePaintable> InlinePaintable::create(Layout::InlineNode const& layout_node)
 {
     return layout_node.heap().allocate_without_realm<InlinePaintable>(layout_node);
diff --git a/Userland/Libraries/LibWeb/Painting/InlinePaintable.h b/Userland/Libraries/LibWeb/Painting/InlinePaintable.h
index 1afe78d4bae..dfb6c3f9e5e 100644
--- a/Userland/Libraries/LibWeb/Painting/InlinePaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/InlinePaintable.h
@@ -14,6 +14,7 @@ namespace Web::Painting {
 
 class InlinePaintable final : public Paintable {
     JS_CELL(InlinePaintable, Paintable);
+    JS_DECLARE_ALLOCATOR(InlinePaintable);
 
 public:
     static JS::NonnullGCPtr<InlinePaintable> create(Layout::InlineNode const&);
diff --git a/Userland/Libraries/LibWeb/Painting/MarkerPaintable.cpp b/Userland/Libraries/LibWeb/Painting/MarkerPaintable.cpp
index 2edae6e3b12..433035b7818 100644
--- a/Userland/Libraries/LibWeb/Painting/MarkerPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/MarkerPaintable.cpp
@@ -12,6 +12,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(MarkerPaintable);
+
 JS::NonnullGCPtr<MarkerPaintable> MarkerPaintable::create(Layout::ListItemMarkerBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<MarkerPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/MarkerPaintable.h b/Userland/Libraries/LibWeb/Painting/MarkerPaintable.h
index 5f18c6a48f4..a0f3ee31e1a 100644
--- a/Userland/Libraries/LibWeb/Painting/MarkerPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/MarkerPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class MarkerPaintable final : public PaintableBox {
     JS_CELL(MarkerPaintable, PaintableBox);
+    JS_DECLARE_ALLOCATOR(MarkerPaintable);
 
 public:
     static JS::NonnullGCPtr<MarkerPaintable> create(Layout::ListItemMarkerBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.cpp b/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.cpp
index 6850da2c693..ba799c2167f 100644
--- a/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.cpp
@@ -14,6 +14,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(NestedBrowsingContextPaintable);
+
 JS::NonnullGCPtr<NestedBrowsingContextPaintable> NestedBrowsingContextPaintable::create(Layout::FrameBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<NestedBrowsingContextPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.h b/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.h
index ca0e1bbbb82..8248e8b0202 100644
--- a/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/NestedBrowsingContextPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class NestedBrowsingContextPaintable final : public PaintableBox {
     JS_CELL(NestedBrowsingContextPaintable, PaintableBox);
+    JS_DECLARE_ALLOCATOR(NestedBrowsingContextPaintable);
 
 public:
     static JS::NonnullGCPtr<NestedBrowsingContextPaintable> create(Layout::FrameBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.cpp b/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.cpp
index c5fe563f00d..cbeadf818a4 100644
--- a/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.cpp
@@ -17,6 +17,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(RadioButtonPaintable);
+
 JS::NonnullGCPtr<RadioButtonPaintable> RadioButtonPaintable::create(Layout::RadioButton const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<RadioButtonPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.h b/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.h
index a0252b8b364..8a89579689f 100644
--- a/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/RadioButtonPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class RadioButtonPaintable final : public LabelablePaintable {
     JS_CELL(RadioButtonPaintable, LabelablePaintable);
+    JS_DECLARE_ALLOCATOR(RadioButtonPaintable);
 
 public:
     static JS::NonnullGCPtr<RadioButtonPaintable> create(Layout::RadioButton const&);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.cpp b/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.cpp
index 42d1cdcdbe6..f10fab1b445 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.cpp
@@ -8,6 +8,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(SVGClipPaintable);
+
 JS::NonnullGCPtr<SVGClipPaintable> SVGClipPaintable::create(Layout::SVGClipBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<SVGClipPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.h
index a49d177fe53..198172a4afb 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGClipPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class SVGClipPaintable : public SVGPaintable {
     JS_CELL(SVGClipPaintable, SVGPaintable);
+    JS_DECLARE_ALLOCATOR(SVGClipPaintable);
 
 public:
     static JS::NonnullGCPtr<SVGClipPaintable> create(Layout::SVGClipBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.cpp b/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.cpp
index 534944f165e..9b1046387a6 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.cpp
@@ -8,6 +8,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(SVGMaskPaintable);
+
 JS::NonnullGCPtr<SVGMaskPaintable> SVGMaskPaintable::create(Layout::SVGMaskBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<SVGMaskPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.h
index b57ab8eaee8..c048d9ccfbf 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGMaskPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class SVGMaskPaintable : public SVGGraphicsPaintable {
     JS_CELL(SVGMaskPaintable, SVGGraphicsPaintable);
+    JS_DECLARE_ALLOCATOR(SVGMaskPaintable);
 
 public:
     static JS::NonnullGCPtr<SVGMaskPaintable> create(Layout::SVGMaskBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.cpp b/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.cpp
index ebd55295c7e..6764d0a8be3 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.cpp
@@ -11,6 +11,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(SVGPathPaintable);
+
 JS::NonnullGCPtr<SVGPathPaintable> SVGPathPaintable::create(Layout::SVGGraphicsBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<SVGPathPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.h
index 5b56a11e5a5..d454924b576 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGPathPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class SVGPathPaintable final : public SVGGraphicsPaintable {
     JS_CELL(SVGPathPaintable, SVGGraphicsPaintable);
+    JS_DECLARE_ALLOCATOR(SVGPathPaintable);
 
 public:
     static JS::NonnullGCPtr<SVGPathPaintable> create(Layout::SVGGraphicsBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.cpp b/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.cpp
index 08dbd6d990b..78146d373e0 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.cpp
@@ -9,6 +9,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(SVGSVGPaintable);
+
 JS::NonnullGCPtr<SVGSVGPaintable> SVGSVGPaintable::create(Layout::SVGSVGBox const& layout_box)
 {
     return layout_box.heap().allocate_without_realm<SVGSVGPaintable>(layout_box);
diff --git a/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h
index b09ce25ffd9..11330d669cf 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class SVGSVGPaintable final : public PaintableBox {
     JS_CELL(SVGSVGPaintable, PaintableBox);
+    JS_DECLARE_ALLOCATOR(SVGSVGPaintable);
 
 public:
     static JS::NonnullGCPtr<SVGSVGPaintable> create(Layout::SVGSVGBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/TextPaintable.cpp b/Userland/Libraries/LibWeb/Painting/TextPaintable.cpp
index 40751247f40..c5cfcbe59c5 100644
--- a/Userland/Libraries/LibWeb/Painting/TextPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/TextPaintable.cpp
@@ -12,6 +12,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(TextPaintable);
+
 JS::NonnullGCPtr<TextPaintable> TextPaintable::create(Layout::TextNode const& layout_node, String const& text_for_rendering)
 {
     return layout_node.heap().allocate_without_realm<TextPaintable>(layout_node, text_for_rendering);
diff --git a/Userland/Libraries/LibWeb/Painting/TextPaintable.h b/Userland/Libraries/LibWeb/Painting/TextPaintable.h
index f32270995ab..5154ddafd73 100644
--- a/Userland/Libraries/LibWeb/Painting/TextPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/TextPaintable.h
@@ -12,6 +12,7 @@ namespace Web::Painting {
 
 class TextPaintable final : public Paintable {
     JS_CELL(TextPaintable, Paintable);
+    JS_DECLARE_ALLOCATOR(TextPaintable);
 
 public:
     static JS::NonnullGCPtr<TextPaintable> create(Layout::TextNode const&, String const& text_for_rendering);
diff --git a/Userland/Libraries/LibWeb/Painting/VideoPaintable.cpp b/Userland/Libraries/LibWeb/Painting/VideoPaintable.cpp
index 20a432f8f92..30680076d0a 100644
--- a/Userland/Libraries/LibWeb/Painting/VideoPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/VideoPaintable.cpp
@@ -20,6 +20,8 @@ namespace Web::Painting {
 static constexpr auto control_box_color = Gfx::Color::from_rgb(0x26'26'26);
 static constexpr auto control_highlight_color = Gfx::Color::from_rgb(0x1d'99'f3);
 
+JS_DEFINE_ALLOCATOR(VideoPaintable);
+
 static constexpr Gfx::Color control_button_color(bool is_hovered)
 {
     if (!is_hovered)
diff --git a/Userland/Libraries/LibWeb/Painting/VideoPaintable.h b/Userland/Libraries/LibWeb/Painting/VideoPaintable.h
index 511e4122c38..4406db734d9 100644
--- a/Userland/Libraries/LibWeb/Painting/VideoPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/VideoPaintable.h
@@ -13,6 +13,7 @@ namespace Web::Painting {
 
 class VideoPaintable final : public MediaPaintable {
     JS_CELL(VideoPaintable, MediaPaintable);
+    JS_DECLARE_ALLOCATOR(VideoPaintable);
 
 public:
     static JS::NonnullGCPtr<VideoPaintable> create(Layout::VideoBox const&);
diff --git a/Userland/Libraries/LibWeb/Painting/ViewportPaintable.cpp b/Userland/Libraries/LibWeb/Painting/ViewportPaintable.cpp
index 20883e57754..2e27a24d01e 100644
--- a/Userland/Libraries/LibWeb/Painting/ViewportPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/ViewportPaintable.cpp
@@ -14,6 +14,8 @@
 
 namespace Web::Painting {
 
+JS_DEFINE_ALLOCATOR(ViewportPaintable);
+
 JS::NonnullGCPtr<ViewportPaintable> ViewportPaintable::create(Layout::Viewport const& layout_viewport)
 {
     return layout_viewport.heap().allocate_without_realm<ViewportPaintable>(layout_viewport);
diff --git a/Userland/Libraries/LibWeb/Painting/ViewportPaintable.h b/Userland/Libraries/LibWeb/Painting/ViewportPaintable.h
index 02a87b8a32b..6708c6e5c2e 100644
--- a/Userland/Libraries/LibWeb/Painting/ViewportPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/ViewportPaintable.h
@@ -12,6 +12,7 @@ namespace Web::Painting {
 
 class ViewportPaintable final : public PaintableWithLines {
     JS_CELL(ViewportPaintable, PaintableWithLines);
+    JS_DECLARE_ALLOCATOR(ViewportPaintable);
 
 public:
     static JS::NonnullGCPtr<ViewportPaintable> create(Layout::Viewport const&);
diff --git a/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.cpp b/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.cpp
index ae6bd03be46..8c84c4730c5 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.cpp
@@ -24,6 +24,7 @@
 namespace Web::SVG {
 
 JS_DEFINE_ALLOCATOR(SVGDecodedImageData);
+JS_DEFINE_ALLOCATOR(SVGDecodedImageData::SVGPageClient);
 
 ErrorOr<JS::NonnullGCPtr<SVGDecodedImageData>> SVGDecodedImageData::create(JS::Realm& realm, JS::NonnullGCPtr<Page> host_page, URL::URL const& url, ByteBuffer data)
 {
diff --git a/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h b/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h
index 399641d6ecf..e7e9eb63b85 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h
+++ b/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h
@@ -52,6 +52,7 @@ private:
 
 class SVGDecodedImageData::SVGPageClient final : public PageClient {
     JS_CELL(SVGDecodedImageData::SVGPageClient, PageClient);
+    JS_DECLARE_ALLOCATOR(SVGDecodedImageData::SVGPageClient);
 
 public:
     static JS::NonnullGCPtr<SVGPageClient> create(JS::VM& vm, Page& page)
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStreamBYOBReader.cpp b/Userland/Libraries/LibWeb/Streams/ReadableStreamBYOBReader.cpp
index b32ee26193f..c71e66d3885 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStreamBYOBReader.cpp
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStreamBYOBReader.cpp
@@ -62,6 +62,7 @@ void ReadableStreamBYOBReader::visit_edges(Cell::Visitor& visitor)
 
 class BYOBReaderReadIntoRequest : public ReadIntoRequest {
     JS_CELL(BYOBReaderReadIntoRequest, ReadIntoRequest);
+    JS_DECLARE_ALLOCATOR(BYOBReaderReadIntoRequest);
 
 public:
     BYOBReaderReadIntoRequest(JS::Realm& realm, WebIDL::Promise& promise)
@@ -103,6 +104,8 @@ private:
     JS::NonnullGCPtr<WebIDL::Promise> m_promise;
 };
 
+JS_DEFINE_ALLOCATOR(BYOBReaderReadIntoRequest);
+
 // https://streams.spec.whatwg.org/#byob-reader-read
 WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::Promise>> ReadableStreamBYOBReader::read(JS::Handle<WebIDL::ArrayBufferView>& view)
 {
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
index 7c2e3107af4..603253b907a 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
@@ -24,6 +24,7 @@
 namespace Web::Streams {
 
 JS_DEFINE_ALLOCATOR(ReadableStreamDefaultReader);
+JS_DEFINE_ALLOCATOR(ReadLoopReadRequest);
 
 void ReadLoopReadRequest::visit_edges(Visitor& visitor)
 {
@@ -116,6 +117,7 @@ void ReadLoopReadRequest::on_error(JS::Value error)
 
 class DefaultReaderReadRequest final : public ReadRequest {
     JS_CELL(DefaultReaderReadRequest, Cell);
+    JS_DECLARE_ALLOCATOR(DefaultReaderReadRequest);
 
 public:
     DefaultReaderReadRequest(JS::Realm& realm, WebIDL::Promise& promise)
@@ -151,6 +153,8 @@ private:
     JS::NonnullGCPtr<WebIDL::Promise> m_promise;
 };
 
+JS_DEFINE_ALLOCATOR(DefaultReaderReadRequest);
+
 // https://streams.spec.whatwg.org/#default-reader-read
 WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::Promise>> ReadableStreamDefaultReader::read()
 {
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h
index 78c3d8e0a40..76ec0460c75 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h
@@ -33,6 +33,7 @@ public:
 
 class ReadLoopReadRequest final : public ReadRequest {
     JS_CELL(ReadLoopReadRequest, JS::Cell);
+    JS_DECLARE_ALLOCATOR(ReadLoopReadRequest);
 
 public:
     // successSteps, which is an algorithm accepting a byte sequence
diff --git a/Userland/Libraries/LibWeb/WebIDL/Buffers.cpp b/Userland/Libraries/LibWeb/WebIDL/Buffers.cpp
index de7fa1a150c..fc164847fb5 100644
--- a/Userland/Libraries/LibWeb/WebIDL/Buffers.cpp
+++ b/Userland/Libraries/LibWeb/WebIDL/Buffers.cpp
@@ -11,6 +11,10 @@
 
 namespace Web::WebIDL {
 
+JS_DEFINE_ALLOCATOR(BufferableObjectBase);
+JS_DEFINE_ALLOCATOR(ArrayBufferView);
+JS_DEFINE_ALLOCATOR(BufferSource);
+
 u32 BufferableObjectBase::byte_length() const
 {
     return m_bufferable_object.visit(
diff --git a/Userland/Libraries/LibWeb/WebIDL/Buffers.h b/Userland/Libraries/LibWeb/WebIDL/Buffers.h
index 848239587d6..bfc07c0a0e8 100644
--- a/Userland/Libraries/LibWeb/WebIDL/Buffers.h
+++ b/Userland/Libraries/LibWeb/WebIDL/Buffers.h
@@ -20,6 +20,7 @@ using BufferableObject = Variant<
 
 class BufferableObjectBase : public JS::Cell {
     JS_CELL(BufferableObjectBase, JS::Cell);
+    JS_DECLARE_ALLOCATOR(BufferableObjectBase);
 
 public:
     virtual ~BufferableObjectBase() override = default;
@@ -54,6 +55,7 @@ protected:
 //          Float32Array or Float64Array or DataView) ArrayBufferView;
 class ArrayBufferView : public BufferableObjectBase {
     JS_CELL(ArrayBufferView, BufferableObjectBase);
+    JS_DECLARE_ALLOCATOR(ArrayBufferView);
 
 public:
     using BufferableObjectBase::BufferableObjectBase;
@@ -71,6 +73,7 @@ public:
 // typedef (ArrayBufferView or ArrayBuffer) BufferSource;
 class BufferSource : public BufferableObjectBase {
     JS_CELL(BufferSource, BufferableObjectBase);
+    JS_DECLARE_ALLOCATOR(BufferSource);
 
 public:
     using BufferableObjectBase::BufferableObjectBase;
diff --git a/Userland/Libraries/LibWeb/WebIDL/ObservableArray.cpp b/Userland/Libraries/LibWeb/WebIDL/ObservableArray.cpp
index a54fc4a4609..567f1402b92 100644
--- a/Userland/Libraries/LibWeb/WebIDL/ObservableArray.cpp
+++ b/Userland/Libraries/LibWeb/WebIDL/ObservableArray.cpp
@@ -9,6 +9,8 @@
 
 namespace Web::WebIDL {
 
+JS_DEFINE_ALLOCATOR(ObservableArray);
+
 JS::NonnullGCPtr<ObservableArray> ObservableArray::create(JS::Realm& realm)
 {
     auto prototype = realm.intrinsics().array_prototype();
diff --git a/Userland/Libraries/LibWeb/WebIDL/ObservableArray.h b/Userland/Libraries/LibWeb/WebIDL/ObservableArray.h
index 0013007df7a..5131ddefb31 100644
--- a/Userland/Libraries/LibWeb/WebIDL/ObservableArray.h
+++ b/Userland/Libraries/LibWeb/WebIDL/ObservableArray.h
@@ -13,6 +13,9 @@ namespace Web::WebIDL {
 
 // https://webidl.spec.whatwg.org/#idl-observable-array
 class ObservableArray final : public JS::Array {
+    JS_OBJECT(ObservableArray, JS::Array);
+    JS_DECLARE_ALLOCATOR(ObservableArray);
+
 public:
     static JS::NonnullGCPtr<ObservableArray> create(JS::Realm& realm);
 
diff --git a/Userland/Libraries/LibWeb/WebIDL/Promise.cpp b/Userland/Libraries/LibWeb/WebIDL/Promise.cpp
index 3b7bda2e4c4..e1873ef68bb 100644
--- a/Userland/Libraries/LibWeb/WebIDL/Promise.cpp
+++ b/Userland/Libraries/LibWeb/WebIDL/Promise.cpp
@@ -176,6 +176,7 @@ void mark_promise_as_handled(Promise const& promise)
 
 struct WaitForAllResults : JS::Cell {
     JS_CELL(WaitForAllResults, JS::Cell);
+    JS_DECLARE_ALLOCATOR(WaitForAllResults);
 
     WaitForAllResults(JS::NonnullGCPtr<JS::HeapFunction<void(Vector<JS::Value> const&)>> s, size_t t)
         : success_steps(s)
@@ -202,6 +203,8 @@ struct WaitForAllResults : JS::Cell {
     size_t fulfilled_count = 0;
 };
 
+JS_DEFINE_ALLOCATOR(WaitForAllResults);
+
 // https://webidl.spec.whatwg.org/#wait-for-all
 void wait_for_all(JS::Realm& realm, Vector<JS::NonnullGCPtr<Promise>> const& promises, Function<void(Vector<JS::Value> const&)> success_steps, Function<void(JS::Value)> failure_steps)
 {