diff --git a/Libraries/LibDevTools/Actors/NodeActor.cpp b/Libraries/LibDevTools/Actors/NodeActor.cpp
index a0021903bbb..2cce2f7cd35 100644
--- a/Libraries/LibDevTools/Actors/NodeActor.cpp
+++ b/Libraries/LibDevTools/Actors/NodeActor.cpp
@@ -5,14 +5,63 @@
  */
 
 #include <AK/JsonObject.h>
+#include <AK/Optional.h>
+#include <AK/Variant.h>
 #include <LibDevTools/Actors/NodeActor.h>
 #include <LibDevTools/Actors/TabActor.h>
 #include <LibDevTools/Actors/WalkerActor.h>
 #include <LibDevTools/DevToolsDelegate.h>
 #include <LibDevTools/DevToolsServer.h>
+#include <LibWebView/Attribute.h>
 
 namespace DevTools {
 
+struct AttributeModification {
+    Optional<String> attribute_to_replace;
+    Vector<WebView::Attribute> replacement_attributes;
+};
+static AttributeModification parse_attribute_modification(JsonArray const& modifications)
+{
+    if (modifications.is_empty())
+        return {};
+
+    Optional<String> attribute_to_replace;
+    Vector<WebView::Attribute> replacement_attributes;
+
+    auto parse_modification = [&](JsonValue const& modification) -> Variant<Empty, String, WebView::Attribute> {
+        if (!modification.is_object())
+            return {};
+
+        auto name = modification.as_object().get_string("attributeName"sv);
+        if (!name.has_value())
+            return {};
+
+        auto value = modification.as_object().get_string("newValue"sv);
+        if (!value.has_value())
+            return *name;
+
+        return WebView::Attribute { *name, *value };
+    };
+
+    auto modification = parse_modification(modifications.at(0));
+    if (modification.has<Empty>())
+        return {};
+
+    modification.visit(
+        [&](String& name) { attribute_to_replace = move(name); },
+        [&](WebView::Attribute& attribute) { replacement_attributes.append(move(attribute)); },
+        [](Empty) { VERIFY_NOT_REACHED(); });
+
+    for (auto i = 1uz; i < modifications.size(); ++i) {
+        auto modification = parse_modification(modifications.at(i));
+
+        if (auto* attribute = modification.get_pointer<WebView::Attribute>())
+            replacement_attributes.empend(move(attribute->name), move(attribute->value));
+    }
+
+    return AttributeModification { move(attribute_to_replace), move(replacement_attributes) };
+}
+
 NodeIdentifier NodeIdentifier::for_node(JsonObject const& node)
 {
     NodeIdentifier identifier;
@@ -57,6 +106,40 @@ void NodeActor::handle_message(StringView type, JsonObject const& message)
         return;
     }
 
+    if (type == "modifyAttributes"sv) {
+        auto modifications = message.get_array("modifications"sv);
+        if (!modifications.has_value()) {
+            send_missing_parameter_error("modifications"sv);
+            return;
+        }
+
+        auto [attribute_to_replace, replacement_attributes] = parse_attribute_modification(*modifications);
+        if (!attribute_to_replace.has_value() && replacement_attributes.is_empty())
+            return;
+
+        if (auto dom_node = WalkerActor::dom_node_for(m_walker, name()); dom_node.has_value()) {
+            auto block_token = block_responses();
+
+            auto on_complete = [weak_self = make_weak_ptr<NodeActor>(), block_token = move(block_token)](ErrorOr<Web::UniqueNodeID> node_id) mutable {
+                if (node_id.is_error()) {
+                    dbgln_if(DEVTOOLS_DEBUG, "Unable to edit DOM node: {}", node_id.error());
+                    return;
+                }
+
+                if (auto self = weak_self.strong_ref())
+                    self->finished_editing_dom_node(move(block_token));
+            };
+
+            if (attribute_to_replace.has_value()) {
+                devtools().delegate().replace_dom_node_attribute(dom_node->tab->description(), dom_node->identifier.id, attribute_to_replace.release_value(), move(replacement_attributes), move(on_complete));
+            } else {
+                devtools().delegate().add_dom_node_attributes(dom_node->tab->description(), dom_node->identifier.id, move(replacement_attributes), move(on_complete));
+            }
+        }
+
+        return;
+    }
+
     if (type == "setNodeValue"sv) {
         auto value = message.get_string("value"sv);
         if (!value.has_value()) {
diff --git a/Libraries/LibDevTools/DevToolsDelegate.h b/Libraries/LibDevTools/DevToolsDelegate.h
index 4ec995e73c2..d31ca0cdda2 100644
--- a/Libraries/LibDevTools/DevToolsDelegate.h
+++ b/Libraries/LibDevTools/DevToolsDelegate.h
@@ -43,6 +43,8 @@ public:
 
     using OnDOMNodeEditComplete = Function<void(ErrorOr<Web::UniqueNodeID>)>;
     virtual void set_dom_node_text(TabDescription const&, Web::UniqueNodeID, String, OnDOMNodeEditComplete) const { }
+    virtual void add_dom_node_attributes(TabDescription const&, Web::UniqueNodeID, Vector<WebView::Attribute>, OnDOMNodeEditComplete) const { }
+    virtual void replace_dom_node_attribute(TabDescription const&, Web::UniqueNodeID, String, Vector<WebView::Attribute>, OnDOMNodeEditComplete) const { }
 
     using OnScriptEvaluationComplete = Function<void(ErrorOr<JsonValue>)>;
     virtual void evaluate_javascript(TabDescription const&, String, OnScriptEvaluationComplete) const { }
diff --git a/Libraries/LibWebView/Application.cpp b/Libraries/LibWebView/Application.cpp
index 744daab7a78..c10fd6aa0cb 100644
--- a/Libraries/LibWebView/Application.cpp
+++ b/Libraries/LibWebView/Application.cpp
@@ -465,6 +465,20 @@ void Application::set_dom_node_text(DevTools::TabDescription const& description,
     });
 }
 
+void Application::add_dom_node_attributes(DevTools::TabDescription const& description, Web::UniqueNodeID node_id, Vector<Attribute> replacement_attributes, OnDOMNodeEditComplete on_complete) const
+{
+    edit_dom_node(description, move(on_complete), [&](auto& view) {
+        view.add_dom_node_attributes(node_id, move(replacement_attributes));
+    });
+}
+
+void Application::replace_dom_node_attribute(DevTools::TabDescription const& description, Web::UniqueNodeID node_id, String name, Vector<Attribute> replacement_attributes, OnDOMNodeEditComplete on_complete) const
+{
+    edit_dom_node(description, move(on_complete), [&](auto& view) {
+        view.replace_dom_node_attribute(node_id, move(name), move(replacement_attributes));
+    });
+}
+
 void Application::evaluate_javascript(DevTools::TabDescription const& description, String script, OnScriptEvaluationComplete on_complete) const
 {
     auto view = ViewImplementation::find_view_by_id(description.id);
diff --git a/Libraries/LibWebView/Application.h b/Libraries/LibWebView/Application.h
index 195d2a9fb0c..acaa3aa2f14 100644
--- a/Libraries/LibWebView/Application.h
+++ b/Libraries/LibWebView/Application.h
@@ -99,6 +99,8 @@ private:
     virtual void listen_for_dom_mutations(DevTools::TabDescription const&, OnDOMMutationReceived) const override;
     virtual void stop_listening_for_dom_mutations(DevTools::TabDescription const&) const override;
     virtual void set_dom_node_text(DevTools::TabDescription const&, Web::UniqueNodeID, String, OnDOMNodeEditComplete) const override;
+    virtual void add_dom_node_attributes(DevTools::TabDescription const&, Web::UniqueNodeID, Vector<Attribute>, OnDOMNodeEditComplete) const override;
+    virtual void replace_dom_node_attribute(DevTools::TabDescription const&, Web::UniqueNodeID, String, Vector<Attribute>, OnDOMNodeEditComplete) const override;
     virtual void evaluate_javascript(DevTools::TabDescription const&, String, OnScriptEvaluationComplete) const override;
     virtual void listen_for_console_messages(DevTools::TabDescription const&, OnConsoleMessageAvailable, OnReceivedConsoleMessages) const override;
     virtual void stop_listening_for_console_messages(DevTools::TabDescription const&) const override;