diff --git a/Libraries/LibWeb/CSS/SelectorEngine.cpp b/Libraries/LibWeb/CSS/SelectorEngine.cpp
index fb08103f660..420018e19e7 100644
--- a/Libraries/LibWeb/CSS/SelectorEngine.cpp
+++ b/Libraries/LibWeb/CSS/SelectorEngine.cpp
@@ -411,7 +411,7 @@ static bool matches_read_write_pseudo_class(DOM::Element const& element)
         return true;
     }
     // - elements that are editing hosts or editable and are neither input elements nor textarea elements
-    return element.is_editable();
+    return element.is_editable_or_editing_host();
 }
 
 // https://www.w3.org/TR/selectors-4/#open-state
diff --git a/Libraries/LibWeb/DOM/Document.cpp b/Libraries/LibWeb/DOM/Document.cpp
index 5a4eb93b8b8..b852554b78b 100644
--- a/Libraries/LibWeb/DOM/Document.cpp
+++ b/Libraries/LibWeb/DOM/Document.cpp
@@ -2000,11 +2000,6 @@ String const& Document::compat_mode() const
     return css1_compat;
 }
 
-bool Document::is_editable() const
-{
-    return m_editable;
-}
-
 // https://html.spec.whatwg.org/multipage/interaction.html#dom-documentorshadowroot-activeelement
 void Document::update_active_element()
 {
@@ -2060,9 +2055,8 @@ void Document::set_focused_element(Element* element)
     if (auto* invalidation_target = find_common_ancestor(old_focused_element, m_focused_element) ?: this)
         invalidation_target->invalidate_style(StyleInvalidationReason::FocusedElementChange);
 
-    if (m_focused_element) {
+    if (m_focused_element)
         m_focused_element->did_receive_focus();
-    }
 
     if (paintable())
         paintable()->set_needs_display();
@@ -5538,7 +5532,7 @@ InputEventsTarget* Document::active_input_events_target()
         return static_cast<HTML::HTMLInputElement*>(focused_element);
     if (is<HTML::HTMLTextAreaElement>(*focused_element))
         return static_cast<HTML::HTMLTextAreaElement*>(focused_element);
-    if (is<HTML::HTMLElement>(*focused_element) && static_cast<HTML::HTMLElement*>(focused_element)->is_editable())
+    if (focused_element->is_editable_or_editing_host())
         return m_editing_host_manager;
     return nullptr;
 }
@@ -5546,9 +5540,8 @@ InputEventsTarget* Document::active_input_events_target()
 GC::Ptr<DOM::Position> Document::cursor_position() const
 {
     auto const* focused_element = this->focused_element();
-    if (!focused_element) {
+    if (!focused_element)
         return nullptr;
-    }
 
     Optional<HTML::FormAssociatedTextControlElement const&> target {};
     if (is<HTML::HTMLInputElement>(*focused_element))
@@ -5556,13 +5549,11 @@ GC::Ptr<DOM::Position> Document::cursor_position() const
     else if (is<HTML::HTMLTextAreaElement>(*focused_element))
         target = static_cast<HTML::HTMLTextAreaElement const&>(*focused_element);
 
-    if (target.has_value()) {
+    if (target.has_value())
         return target->cursor_position();
-    }
 
-    if (is<HTML::HTMLElement>(*focused_element) && static_cast<HTML::HTMLElement const*>(focused_element)->is_editable()) {
+    if (focused_element->is_editable_or_editing_host())
         return m_selection->cursor_position();
-    }
 
     return nullptr;
 }
diff --git a/Libraries/LibWeb/DOM/Document.h b/Libraries/LibWeb/DOM/Document.h
index 9c5661cf37e..f8cd52a6e88 100644
--- a/Libraries/LibWeb/DOM/Document.h
+++ b/Libraries/LibWeb/DOM/Document.h
@@ -335,7 +335,6 @@ public:
     String const& compat_mode() const;
 
     void set_editable(bool editable) { m_editable = editable; }
-    virtual bool is_editable() const final;
 
     Element* focused_element() { return m_focused_element.ptr(); }
     Element const* focused_element() const { return m_focused_element.ptr(); }
diff --git a/Libraries/LibWeb/DOM/EditingHostManager.cpp b/Libraries/LibWeb/DOM/EditingHostManager.cpp
index f66486833b2..0e1f20e7c9d 100644
--- a/Libraries/LibWeb/DOM/EditingHostManager.cpp
+++ b/Libraries/LibWeb/DOM/EditingHostManager.cpp
@@ -36,14 +36,12 @@ void EditingHostManager::handle_insert(String const& data)
     auto selection = m_document->get_selection();
 
     auto selection_range = selection->range();
-    if (!selection_range) {
+    if (!selection_range)
         return;
-    }
 
     auto node = selection->anchor_node();
-    if (!node || !node->is_editable()) {
+    if (!node || !node->is_editable_or_editing_host())
         return;
-    }
 
     if (!is<DOM::Text>(*node)) {
         auto& realm = node->realm();
diff --git a/Libraries/LibWeb/DOM/Node.cpp b/Libraries/LibWeb/DOM/Node.cpp
index a57185b5a54..c349c5f6a7b 100644
--- a/Libraries/LibWeb/DOM/Node.cpp
+++ b/Libraries/LibWeb/DOM/Node.cpp
@@ -2,6 +2,7 @@
  * Copyright (c) 2018-2024, Andreas Kling <andreas@ladybird.org>
  * Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
  * Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -11,7 +12,6 @@
 #include <LibGC/DeferGC.h>
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibRegex/Regex.h>
-#include <LibURL/Origin.h>
 #include <LibWeb/Bindings/MainThreadVM.h>
 #include <LibWeb/Bindings/NodePrototype.h>
 #include <LibWeb/DOM/Attr.h>
@@ -44,16 +44,18 @@
 #include <LibWeb/HTML/HTMLSlotElement.h>
 #include <LibWeb/HTML/HTMLStyleElement.h>
 #include <LibWeb/HTML/HTMLTableElement.h>
+#include <LibWeb/HTML/HTMLTextAreaElement.h>
 #include <LibWeb/HTML/Navigable.h>
 #include <LibWeb/HTML/NavigableContainer.h>
 #include <LibWeb/HTML/Parser/HTMLParser.h>
 #include <LibWeb/Infra/CharacterTypes.h>
 #include <LibWeb/Layout/Node.h>
 #include <LibWeb/Layout/TextNode.h>
-#include <LibWeb/Layout/Viewport.h>
+#include <LibWeb/MathML/MathMLElement.h>
 #include <LibWeb/Namespace.h>
 #include <LibWeb/Painting/Paintable.h>
 #include <LibWeb/Painting/PaintableBox.h>
+#include <LibWeb/SVG/SVGElement.h>
 #include <LibWeb/SVG/SVGTitleElement.h>
 #include <LibWeb/XLink/AttributeNames.h>
 
@@ -1183,9 +1185,48 @@ void Node::set_document(Badge<Document>, Document& document)
     }
 }
 
+// https://w3c.github.io/editing/docs/execCommand/#editable
 bool Node::is_editable() const
 {
-    return parent() && parent()->is_editable();
+    // Something is editable if it is a node; it is not an editing host;
+    if (is_editing_host())
+        return false;
+
+    // it does not have a contenteditable attribute set to the false state;
+    if (is<HTML::HTMLElement>(this) && static_cast<HTML::HTMLElement const&>(*this).content_editable_state() == HTML::ContentEditableState::False)
+        return false;
+
+    // its parent is an editing host or editable;
+    if (!parent() || !parent()->is_editable_or_editing_host())
+        return false;
+
+    // and either it is an HTML element,
+    if (is<HTML::HTMLElement>(this))
+        return true;
+
+    // or it is an svg or math element,
+    if (is<SVG::SVGElement>(this) || is<MathML::MathMLElement>(this))
+        return true;
+
+    // or it is not an Element and its parent is an HTML element.
+    return !is<Element>(this) && is<HTML::HTMLElement>(parent());
+}
+
+// https://html.spec.whatwg.org/multipage/interaction.html#editing-host
+bool Node::is_editing_host() const
+{
+    // NOTE: Both conditions below require this to be an HTML element.
+    if (!is<HTML::HTMLElement>(this))
+        return false;
+
+    // An editing host is either an HTML element with its contenteditable attribute in the true state or
+    // plaintext-only state,
+    auto state = static_cast<HTML::HTMLElement const&>(*this).content_editable_state();
+    if (state == HTML::ContentEditableState::True || state == HTML::ContentEditableState::PlaintextOnly)
+        return true;
+
+    // or a child HTML element of a Document whose design mode enabled is true.
+    return is<Document>(parent()) && static_cast<Document const&>(*parent()).design_mode_enabled_state();
 }
 
 void Node::set_layout_node(Badge<Layout::Node>, GC::Ref<Layout::Node> layout_node)
diff --git a/Libraries/LibWeb/DOM/Node.h b/Libraries/LibWeb/DOM/Node.h
index 64499ee7c03..f1e509e872c 100644
--- a/Libraries/LibWeb/DOM/Node.h
+++ b/Libraries/LibWeb/DOM/Node.h
@@ -137,7 +137,9 @@ public:
     // NOTE: This is intended for the JS bindings.
     u16 node_type() const { return (u16)m_type; }
 
-    virtual bool is_editable() const;
+    bool is_editable() const;
+    bool is_editing_host() const;
+    bool is_editable_or_editing_host() const { return is_editable() || is_editing_host(); }
 
     virtual bool is_dom_node() const final { return true; }
     virtual bool is_html_element() const { return false; }
diff --git a/Libraries/LibWeb/DOM/Text.h b/Libraries/LibWeb/DOM/Text.h
index 1010858777b..d7ebcf038ca 100644
--- a/Libraries/LibWeb/DOM/Text.h
+++ b/Libraries/LibWeb/DOM/Text.h
@@ -26,9 +26,6 @@ public:
 
     // ^Node
     virtual FlyString node_name() const override { return "#text"_fly_string; }
-    virtual bool is_editable() const override { return m_always_editable || CharacterData::is_editable(); }
-
-    void set_always_editable(bool b) { m_always_editable = b; }
 
     Optional<size_t> max_length() const { return m_max_length; }
     void set_max_length(Optional<size_t> max_length) { m_max_length = move(max_length); }
@@ -51,7 +48,6 @@ protected:
 private:
     GC::Ptr<Element> m_owner;
 
-    bool m_always_editable { false };
     Optional<size_t> m_max_length {};
     bool m_is_password_input { false };
 };
diff --git a/Libraries/LibWeb/Editing/Commands.cpp b/Libraries/LibWeb/Editing/Commands.cpp
index 8b370c382be..0dd3ac71c02 100644
--- a/Libraries/LibWeb/Editing/Commands.cpp
+++ b/Libraries/LibWeb/Editing/Commands.cpp
@@ -384,7 +384,7 @@ bool command_insert_paragraph_action(DOM::Document& document, String const&)
     // 2. If the active range's start node is neither editable nor an editing host, return true.
     auto& active_range = *selection.range();
     GC::Ptr<DOM::Node> node = active_range.start_container();
-    if (!node->is_editable() && !is_editing_host(*node))
+    if (!node->is_editable_or_editing_host())
         return true;
 
     // 3. Let node and offset be the active range's start node and offset.
diff --git a/Libraries/LibWeb/Editing/ExecCommand.cpp b/Libraries/LibWeb/Editing/ExecCommand.cpp
index ae709735709..5d65ead33ef 100644
--- a/Libraries/LibWeb/Editing/ExecCommand.cpp
+++ b/Libraries/LibWeb/Editing/ExecCommand.cpp
@@ -118,7 +118,7 @@ bool Document::query_command_enabled(FlyString const& command)
 
     // its start node is either editable or an editing host,
     auto start_node = active_range->start_container();
-    if (!start_node->is_editable() && !Editing::is_editing_host(start_node))
+    if (!start_node->is_editable_or_editing_host())
         return false;
 
     // FIXME: the editing host of its start node is not an EditContext editing host,
@@ -126,7 +126,7 @@ bool Document::query_command_enabled(FlyString const& command)
 
     // its end node is either editable or an editing host,
     auto& end_node = *active_range->end_container();
-    if (!end_node.is_editable() && !Editing::is_editing_host(end_node))
+    if (!end_node.is_editable_or_editing_host())
         return false;
 
     // FIXME: the editing host of its end node is not an EditContext editing host,
diff --git a/Libraries/LibWeb/Editing/Internal/Algorithms.cpp b/Libraries/LibWeb/Editing/Internal/Algorithms.cpp
index 754f03ecd3f..daa6b975ef9 100644
--- a/Libraries/LibWeb/Editing/Internal/Algorithms.cpp
+++ b/Libraries/LibWeb/Editing/Internal/Algorithms.cpp
@@ -201,7 +201,7 @@ String canonical_space_sequence(u32 length, bool non_breaking_start, bool non_br
 void canonicalize_whitespace(GC::Ref<DOM::Node> node, u32 offset, bool fix_collapsed_space)
 {
     // 1. If node is neither editable nor an editing host, abort these steps.
-    if (!node->is_editable() || !is_editing_host(node))
+    if (!node->is_editable_or_editing_host())
         return;
 
     // 2. Let start node equal node and let start offset equal offset.
@@ -916,20 +916,6 @@ bool is_collapsed_whitespace_node(GC::Ref<DOM::Node> node)
     return false;
 }
 
-// https://html.spec.whatwg.org/multipage/interaction.html#editing-host
-bool is_editing_host(GC::Ref<DOM::Node> node)
-{
-    // An editing host is either an HTML element with its contenteditable attribute in the true
-    // state or plaintext-only state, or a child HTML element of a Document whose design mode
-    // enabled is true.
-    if (!is<HTML::HTMLElement>(*node))
-        return false;
-    auto const& html_element = static_cast<HTML::HTMLElement&>(*node);
-    return html_element.content_editable_state() == HTML::ContentEditableState::True
-        || html_element.content_editable_state() == HTML::ContentEditableState::PlaintextOnly
-        || node->document().design_mode_enabled_state();
-}
-
 // https://w3c.github.io/editing/docs/execCommand/#element-with-inline-contents
 bool is_element_with_inline_contents(GC::Ref<DOM::Node> node)
 {
diff --git a/Libraries/LibWeb/Editing/Internal/Algorithms.h b/Libraries/LibWeb/Editing/Internal/Algorithms.h
index 441a708990d..e46b26c6c67 100644
--- a/Libraries/LibWeb/Editing/Internal/Algorithms.h
+++ b/Libraries/LibWeb/Editing/Internal/Algorithms.h
@@ -34,7 +34,6 @@ bool is_block_end_point(GC::Ref<DOM::Node>, u32 offset);
 bool is_block_node(GC::Ref<DOM::Node>);
 bool is_block_start_point(GC::Ref<DOM::Node>, u32 offset);
 bool is_collapsed_whitespace_node(GC::Ref<DOM::Node>);
-bool is_editing_host(GC::Ref<DOM::Node>);
 bool is_element_with_inline_contents(GC::Ref<DOM::Node>);
 bool is_extraneous_line_break(GC::Ref<DOM::Node>);
 bool is_in_same_editing_host(GC::Ref<DOM::Node>, GC::Ref<DOM::Node>);
diff --git a/Libraries/LibWeb/HTML/FormAssociatedElement.cpp b/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
index a187d32f11a..6927d7812ae 100644
--- a/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
+++ b/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
@@ -588,7 +588,7 @@ void FormAssociatedTextControlElement::set_the_selection_range(Optional<WebIDL::
 void FormAssociatedTextControlElement::handle_insert(String const& data)
 {
     auto text_node = form_associated_element_to_text_node();
-    if (!text_node || !text_node->is_editable())
+    if (!text_node || !is_mutable())
         return;
 
     String data_for_insertion = data;
@@ -613,7 +613,7 @@ void FormAssociatedTextControlElement::handle_insert(String const& data)
 void FormAssociatedTextControlElement::handle_delete(DeleteDirection direction)
 {
     auto text_node = form_associated_element_to_text_node();
-    if (!text_node || !text_node->is_editable())
+    if (!text_node || !is_mutable())
         return;
     auto selection_start = this->selection_start();
     auto selection_end = this->selection_end();
diff --git a/Libraries/LibWeb/HTML/FormAssociatedElement.h b/Libraries/LibWeb/HTML/FormAssociatedElement.h
index 66e12a26eb7..bf2c53f74e2 100644
--- a/Libraries/LibWeb/HTML/FormAssociatedElement.h
+++ b/Libraries/LibWeb/HTML/FormAssociatedElement.h
@@ -170,6 +170,9 @@ public:
     bool has_scheduled_selectionchange_event() const { return m_has_scheduled_selectionchange_event; }
     void set_scheduled_selectionchange_event(bool value) { m_has_scheduled_selectionchange_event = value; }
 
+    bool is_mutable() const { return m_is_mutable; }
+    void set_is_mutable(bool is_mutable) { m_is_mutable = is_mutable; }
+
     virtual void did_edit_text_node() = 0;
 
     virtual GC::Ptr<DOM::Text> form_associated_element_to_text_node() = 0;
@@ -205,6 +208,9 @@ private:
 
     // https://w3c.github.io/selection-api/#dfn-has-scheduled-selectionchange-event
     bool m_has_scheduled_selectionchange_event { false };
+
+    // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#mutability
+    bool m_is_mutable { true };
 };
 
 }
diff --git a/Libraries/LibWeb/HTML/HTMLElement.cpp b/Libraries/LibWeb/HTML/HTMLElement.cpp
index bb61449831d..001ee6d104c 100644
--- a/Libraries/LibWeb/HTML/HTMLElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLElement.cpp
@@ -86,25 +86,9 @@ void HTMLElement::set_dir(String const& dir)
     MUST(set_attribute(HTML::AttributeNames::dir, dir));
 }
 
-bool HTMLElement::is_editable() const
-{
-    switch (m_content_editable_state) {
-    case ContentEditableState::True:
-    case ContentEditableState::PlaintextOnly:
-        return true;
-    case ContentEditableState::False:
-        return false;
-    case ContentEditableState::Inherit:
-        return parent() && parent()->is_editable();
-    default:
-        VERIFY_NOT_REACHED();
-    }
-}
-
 bool HTMLElement::is_focusable() const
 {
-    return m_content_editable_state == ContentEditableState::True
-        || m_content_editable_state == ContentEditableState::PlaintextOnly;
+    return is_editing_host();
 }
 
 // https://html.spec.whatwg.org/multipage/interaction.html#dom-iscontenteditable
@@ -112,7 +96,7 @@ bool HTMLElement::is_content_editable() const
 {
     // The isContentEditable IDL attribute, on getting, must return true if the element is either an editing host or
     // editable, and false otherwise.
-    return is_editable();
+    return is_editable_or_editing_host();
 }
 
 StringView HTMLElement::content_editable() const
@@ -1181,7 +1165,7 @@ WebIDL::ExceptionOr<bool> HTMLElement::toggle_popover(TogglePopoverOptionsOrForc
 
 void HTMLElement::did_receive_focus()
 {
-    if (m_content_editable_state != ContentEditableState::True)
+    if (!first_is_one_of(m_content_editable_state, ContentEditableState::True, ContentEditableState::PlaintextOnly))
         return;
 
     auto editing_host = document().editing_host_manager();
@@ -1202,7 +1186,7 @@ void HTMLElement::did_receive_focus()
 
 void HTMLElement::did_lose_focus()
 {
-    if (m_content_editable_state != ContentEditableState::True)
+    if (!first_is_one_of(m_content_editable_state, ContentEditableState::True, ContentEditableState::PlaintextOnly))
         return;
 
     document().editing_host_manager()->set_active_contenteditable_element(nullptr);
diff --git a/Libraries/LibWeb/HTML/HTMLElement.h b/Libraries/LibWeb/HTML/HTMLElement.h
index 77c67f50558..ac52ac3e53c 100644
--- a/Libraries/LibWeb/HTML/HTMLElement.h
+++ b/Libraries/LibWeb/HTML/HTMLElement.h
@@ -73,7 +73,6 @@ public:
     StringView dir() const;
     void set_dir(String const&);
 
-    virtual bool is_editable() const final;
     virtual bool is_focusable() const override;
     bool is_content_editable() const;
     StringView content_editable() const;
diff --git a/Libraries/LibWeb/HTML/HTMLInputElement.cpp b/Libraries/LibWeb/HTML/HTMLInputElement.cpp
index bec7f08eeb1..c4a6d14a9bd 100644
--- a/Libraries/LibWeb/HTML/HTMLInputElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLInputElement.cpp
@@ -336,7 +336,7 @@ WebIDL::ExceptionOr<void> HTMLInputElement::show_picker()
     // The showPicker() method steps are:
 
     // 1. If this is not mutable, then throw an "InvalidStateError" DOMException.
-    if (!m_is_mutable)
+    if (!is_mutable())
         return WebIDL::InvalidStateError::create(realm(), "Element is not mutable"_string);
 
     // 2. If this's relevant settings object's origin is not same origin with this's relevant settings object's top-level origin,
@@ -712,10 +712,7 @@ void HTMLInputElement::handle_maxlength_attribute()
 void HTMLInputElement::handle_readonly_attribute(Optional<String> const& maybe_value)
 {
     // The readonly attribute is a boolean attribute that controls whether or not the user can edit the form control. When specified, the element is not mutable.
-    m_is_mutable = !maybe_value.has_value() || !is_allowed_to_be_readonly(m_type);
-
-    if (m_text_node)
-        m_text_node->set_always_editable(m_is_mutable);
+    set_is_mutable(!maybe_value.has_value() || !is_allowed_to_be_readonly(m_type));
 }
 
 // https://html.spec.whatwg.org/multipage/input.html#the-input-element:attr-input-placeholder-3
@@ -871,12 +868,7 @@ void HTMLInputElement::create_text_input_shadow_tree()
     MUST(element->append_child(*m_inner_text_element));
 
     m_text_node = realm().create<DOM::Text>(document(), move(initial_value));
-    if (type_state() == TypeAttributeState::FileUpload) {
-        // NOTE: file upload state is mutable, but we don't allow the text node to be modifed
-        m_text_node->set_always_editable(false);
-    } else {
-        handle_readonly_attribute(attribute(HTML::AttributeNames::readonly));
-    }
+    handle_readonly_attribute(attribute(HTML::AttributeNames::readonly));
     if (type_state() == TypeAttributeState::Password)
         m_text_node->set_is_password_input({}, true);
     handle_maxlength_attribute();
@@ -907,7 +899,7 @@ void HTMLInputElement::create_text_input_shadow_tree()
 
         auto up_callback_function = JS::NativeFunction::create(
             realm(), [this](JS::VM&) {
-                if (m_is_mutable) {
+                if (is_mutable()) {
                     MUST(step_up());
                     user_interaction_did_change_input_value();
                 }
@@ -929,7 +921,7 @@ void HTMLInputElement::create_text_input_shadow_tree()
 
         auto down_callback_function = JS::NativeFunction::create(
             realm(), [this](JS::VM&) {
-                if (m_is_mutable) {
+                if (is_mutable()) {
                     MUST(step_down());
                     user_interaction_did_change_input_value();
                 }
diff --git a/Libraries/LibWeb/HTML/HTMLInputElement.h b/Libraries/LibWeb/HTML/HTMLInputElement.h
index 30369be9abe..bf2df331779 100644
--- a/Libraries/LibWeb/HTML/HTMLInputElement.h
+++ b/Libraries/LibWeb/HTML/HTMLInputElement.h
@@ -100,8 +100,6 @@ public:
     bool indeterminate() const { return m_indeterminate; }
     void set_indeterminate(bool);
 
-    bool is_mutable() const { return m_is_mutable; }
-
     void did_pick_color(Optional<Color> picked_color, ColorPickerUpdateState state);
 
     enum class MultipleHandling {
@@ -339,9 +337,6 @@ private:
     // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#concept-fe-dirty
     bool m_dirty_value { false };
 
-    // https://html.spec.whatwg.org/multipage/input.html#the-input-element:concept-fe-mutable
-    bool m_is_mutable { true };
-
     // https://html.spec.whatwg.org/multipage/input.html#the-input-element:legacy-pre-activation-behavior
     bool m_before_legacy_pre_activation_behavior_checked { false };
     bool m_before_legacy_pre_activation_behavior_indeterminate { false };
diff --git a/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp b/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
index 6aeb1363cc3..89f2bdac319 100644
--- a/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
@@ -394,10 +394,7 @@ void HTMLTextAreaElement::create_shadow_tree_if_needed()
 void HTMLTextAreaElement::handle_readonly_attribute(Optional<String> const& maybe_value)
 {
     // The readonly attribute is a boolean attribute that controls whether or not the user can edit the form control. When specified, the element is not mutable.
-    m_is_mutable = !maybe_value.has_value();
-
-    if (m_text_node)
-        m_text_node->set_always_editable(m_is_mutable);
+    set_is_mutable(!maybe_value.has_value());
 }
 
 // https://html.spec.whatwg.org/multipage/form-elements.html#dom-textarea-maxlength
diff --git a/Libraries/LibWeb/HTML/HTMLTextAreaElement.h b/Libraries/LibWeb/HTML/HTMLTextAreaElement.h
index e26905cf107..3053f63d2da 100644
--- a/Libraries/LibWeb/HTML/HTMLTextAreaElement.h
+++ b/Libraries/LibWeb/HTML/HTMLTextAreaElement.h
@@ -157,9 +157,6 @@ private:
     // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#concept-fe-dirty
     bool m_dirty_value { false };
 
-    // https://html.spec.whatwg.org/multipage/form-elements.html#the-textarea-element:concept-fe-mutable
-    bool m_is_mutable { true };
-
     // https://html.spec.whatwg.org/multipage/form-elements.html#concept-textarea-raw-value
     String m_raw_value;
 
diff --git a/Libraries/LibWeb/Page/DragAndDropEventHandler.cpp b/Libraries/LibWeb/Page/DragAndDropEventHandler.cpp
index 452f77cd6b3..7a966821fbe 100644
--- a/Libraries/LibWeb/Page/DragAndDropEventHandler.cpp
+++ b/Libraries/LibWeb/Page/DragAndDropEventHandler.cpp
@@ -611,7 +611,7 @@ bool DragAndDropEventHandler::allow_text_drop(GC::Ref<DOM::Node> node) const
     if (!m_drag_data_store->has_text_item())
         return false;
 
-    if (node->is_editable())
+    if (node->is_editable_or_editing_host())
         return true;
 
     if (is<HTML::HTMLTextAreaElement>(*node))
diff --git a/Libraries/LibWeb/Painting/PaintableBox.cpp b/Libraries/LibWeb/Painting/PaintableBox.cpp
index 1ff3e147770..f79d1f41d07 100644
--- a/Libraries/LibWeb/Painting/PaintableBox.cpp
+++ b/Libraries/LibWeb/Painting/PaintableBox.cpp
@@ -564,7 +564,12 @@ void paint_cursor_if_needed(PaintContext& context, TextPaintable const& paintabl
     if (cursor_position->offset() < (unsigned)fragment.start() || cursor_position->offset() > (unsigned)(fragment.start() + fragment.length()))
         return;
 
-    if (!fragment.layout_node().dom_node() || !fragment.layout_node().dom_node()->is_editable())
+    auto active_element = document.active_element();
+    auto active_element_is_editable = is<HTML::FormAssociatedTextControlElement>(active_element)
+        && dynamic_cast<HTML::FormAssociatedTextControlElement const&>(*active_element).is_mutable();
+
+    auto dom_node = fragment.layout_node().dom_node();
+    if (!dom_node || (!dom_node->is_editable() && !active_element_is_editable))
         return;
 
     auto fragment_rect = fragment.absolute_rect();
diff --git a/Libraries/LibWeb/WebDriver/ElementReference.cpp b/Libraries/LibWeb/WebDriver/ElementReference.cpp
index e77518a5dee..5d116a4edb4 100644
--- a/Libraries/LibWeb/WebDriver/ElementReference.cpp
+++ b/Libraries/LibWeb/WebDriver/ElementReference.cpp
@@ -288,11 +288,7 @@ bool is_element_editable(Web::DOM::Element const& element)
 bool is_element_mutable(Web::DOM::Element const& element)
 {
     // Denotes elements that are editing hosts or content editable.
-    if (!is<HTML::HTMLElement>(element))
-        return false;
-
-    auto const& html_element = static_cast<HTML::HTMLElement const&>(element);
-    return html_element.is_editable();
+    return element.is_editable_or_editing_host();
 }
 
 // https://w3c.github.io/webdriver/#dfn-mutable-form-control-element