diff --git a/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp b/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp
index d9d4f45869..c46b435a4b 100644
--- a/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp
+++ b/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp
@@ -881,20 +881,6 @@ BrowsingContext::ChosenBrowsingContext BrowsingContext::choose_a_browsing_contex
     return { chosen.ptr(), window_type };
 }
 
-// https://html.spec.whatwg.org/multipage/browsers.html#document-tree-child-browsing-context
-size_t BrowsingContext::document_tree_child_browsing_context_count() const
-{
-    size_t count = 0;
-
-    // A browsing context child is a document-tree child browsing context of parent if child is a child browsing context and child's container is in a document tree.
-    for_each_child([this, &count](BrowsingContext const& child) {
-        if (child.is_child_of(*this) && child.container()->in_a_document_tree())
-            ++count;
-    });
-
-    return count;
-}
-
 // https://html.spec.whatwg.org/multipage/browsers.html#child-browsing-context
 bool BrowsingContext::is_child_of(BrowsingContext const& parent) const
 {
diff --git a/Userland/Libraries/LibWeb/HTML/BrowsingContext.h b/Userland/Libraries/LibWeb/HTML/BrowsingContext.h
index e09220e4f1..8646a1b006 100644
--- a/Userland/Libraries/LibWeb/HTML/BrowsingContext.h
+++ b/Userland/Libraries/LibWeb/HTML/BrowsingContext.h
@@ -169,8 +169,6 @@ public:
 
     ChosenBrowsingContext choose_a_browsing_context(StringView name, TokenizedFeature::NoOpener no_opener, ActivateTab = ActivateTab::Yes);
 
-    size_t document_tree_child_browsing_context_count() const;
-
     bool is_child_of(BrowsingContext const&) const;
 
     HTML::NavigableContainer* container() { return m_container; }
diff --git a/Userland/Libraries/LibWeb/HTML/Window.cpp b/Userland/Libraries/LibWeb/HTML/Window.cpp
index 780fdc5375..832e42c7f9 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Window.cpp
@@ -1394,16 +1394,4 @@ JS::NonnullGCPtr<CustomElementRegistry> Window::custom_elements()
     return JS::NonnullGCPtr { *m_custom_element_registry };
 }
 
-// https://html.spec.whatwg.org/multipage/window-object.html#number-of-document-tree-child-browsing-contexts
-size_t Window::document_tree_child_browsing_context_count() const
-{
-    // 1. If W's browsing context is null, then return 0.
-    auto* this_browsing_context = associated_document().browsing_context();
-    if (!this_browsing_context)
-        return 0;
-
-    // 2. Return the number of document-tree child browsing contexts of W's browsing context.
-    return this_browsing_context->document_tree_child_browsing_context_count();
-}
-
 }
diff --git a/Userland/Libraries/LibWeb/HTML/Window.h b/Userland/Libraries/LibWeb/HTML/Window.h
index 2b8f47dfe1..0a1be8341e 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.h
+++ b/Userland/Libraries/LibWeb/HTML/Window.h
@@ -85,8 +85,6 @@ public:
 
     JS::GCPtr<Navigable> navigable() const;
 
-    size_t document_tree_child_browsing_context_count() const;
-
     ImportMap const& import_map() const { return m_import_map; }
 
     bool import_maps_allowed() const { return m_import_maps_allowed; }