diff --git a/LayoutTests/platform/wk2/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt b/LayoutTests/platform/wk2/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt
index e5c7ca454678..c2a845973b2a 100644
--- a/LayoutTests/platform/wk2/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt
+++ b/LayoutTests/platform/wk2/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt
@@ -6,11 +6,11 @@ frame "<!--frame1-->" - didStartProvisionalLoadForFrame
 resources/subresource-null-mimetype.webarchive - willSendRequest <NSURLRequest URL resources/subresource-null-mimetype.webarchive, main document URL test-loading-archive-subresource-null-mimetype.html, http method GET> redirectResponse (null)
 resources/subresource-null-mimetype.webarchive - didReceiveResponse <NSURLResponse resources/subresource-null-mimetype.webarchive, http status code 0>
 frame "<!--frame1-->" - didCommitLoadForFrame
-webarchive+file:///test.png - willSendRequest <NSURLRequest URL webarchive+file:///test.png, main document URL test-loading-archive-subresource-null-mimetype.html, http method GET> redirectResponse (null)
+test.png - willSendRequest <NSURLRequest URL test.png, main document URL test-loading-archive-subresource-null-mimetype.html, http method GET> redirectResponse (null)
 frame "<!--frame1-->" - didFinishDocumentLoadForFrame
 resources/subresource-null-mimetype.webarchive - didFinishLoading
-webarchive+file:///test.png - didReceiveResponse <NSURLResponse webarchive+file:///test.png, http status code 0>
-webarchive+file:///test.png - didFinishLoading
+test.png - didReceiveResponse <NSURLResponse test.png, http status code 0>
+test.png - didFinishLoading
 frame "<!--frame1-->" - didHandleOnloadEventsForFrame
 main frame - didHandleOnloadEventsForFrame
 frame "<!--frame1-->" - didFinishLoadForFrame
diff --git a/LayoutTests/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt b/LayoutTests/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt
index 54a3b6b466b0..0385e3913841 100644
--- a/LayoutTests/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt
+++ b/LayoutTests/webarchive/loading/test-loading-archive-subresource-null-mimetype-expected.txt
@@ -6,11 +6,11 @@ main frame - didFinishDocumentLoadForFrame
 test-loading-archive-subresource-null-mimetype.html - didFinishLoading
 resources/subresource-null-mimetype.webarchive - didReceiveResponse <NSURLResponse resources/subresource-null-mimetype.webarchive, http status code 0>
 frame "<!--frame1-->" - didCommitLoadForFrame
-webarchive+file:///test.png - willSendRequest <NSURLRequest URL webarchive+file:///test.png, main document URL test-loading-archive-subresource-null-mimetype.html, http method GET> redirectResponse (null)
+test.png - willSendRequest <NSURLRequest URL test.png, main document URL test-loading-archive-subresource-null-mimetype.html, http method GET> redirectResponse (null)
 frame "<!--frame1-->" - didFinishDocumentLoadForFrame
 resources/subresource-null-mimetype.webarchive - didFinishLoading
-webarchive+file:///test.png - didReceiveResponse <NSURLResponse webarchive+file:///test.png, http status code 0>
-webarchive+file:///test.png - didFinishLoading
+test.png - didReceiveResponse <NSURLResponse test.png, http status code 0>
+test.png - didFinishLoading
 frame "<!--frame1-->" - didHandleOnloadEventsForFrame
 main frame - didHandleOnloadEventsForFrame
 frame "<!--frame1-->" - didFinishLoadForFrame
diff --git a/Source/WTF/Scripts/Preferences/WebPreferences.yaml b/Source/WTF/Scripts/Preferences/WebPreferences.yaml
index 253a1cb242be..89650e31c220 100644
--- a/Source/WTF/Scripts/Preferences/WebPreferences.yaml
+++ b/Source/WTF/Scripts/Preferences/WebPreferences.yaml
@@ -2481,17 +2481,6 @@ WebArchiveDebugModeEnabled:
     WebCore:
       default: false
 
-WebArchiveTestingModeEnabled:
-  type: bool
-  condition: ENABLE(WEB_ARCHIVE)
-  defaultValue:
-    WebKitLegacy:
-      default: false
-    WebKit:
-      default: false
-    WebCore:
-      default: false
-
 WebAudioEnabled:
   type: bool
   condition: ENABLE(WEB_AUDIO)
diff --git a/Source/WebCore/editing/cocoa/WebContentReaderCocoa.mm b/Source/WebCore/editing/cocoa/WebContentReaderCocoa.mm
index 90ab6e95661a..9b62b7f10078 100644
--- a/Source/WebCore/editing/cocoa/WebContentReaderCocoa.mm
+++ b/Source/WebCore/editing/cocoa/WebContentReaderCocoa.mm
@@ -429,7 +429,7 @@ static void replaceRichContentWithAttachments(Frame& frame, DocumentFragment& fr
 
 static std::optional<MarkupAndArchive> extractMarkupAndArchive(SharedBuffer& buffer, const std::function<bool(const String)>& canShowMIMETypeAsHTML)
 {
-    auto archive = LegacyWebArchive::create(buffer);
+    auto archive = LegacyWebArchive::create(URL(), buffer);
     if (!archive)
         return std::nullopt;
 
diff --git a/Source/WebCore/loader/DocumentLoader.cpp b/Source/WebCore/loader/DocumentLoader.cpp
index 7a907db28ee9..8988e7c1b366 100644
--- a/Source/WebCore/loader/DocumentLoader.cpp
+++ b/Source/WebCore/loader/DocumentLoader.cpp
@@ -1212,21 +1212,6 @@ static inline bool shouldUseActiveServiceWorkerFromParent(const Document& docume
 }
 #endif
 
-#if ENABLE(WEB_ARCHIVE) || ENABLE(MHTML)
-bool DocumentLoader::isLoadingRemoteArchive() const
-{
-#if ENABLE(MHTML)
-    return m_archive && m_archive->shouldOverrideBaseURL();
-#else
-    bool isQuickLookPreview = false;
-#if USE(QUICK_LOOK)
-    isQuickLookPreview = isQuickLookPreviewURL(m_response.url());
-#endif // QUICK_LOOK
-    return m_archive && !m_frame->settings().webArchiveTestingModeEnabled() && !isQuickLookPreview;
-#endif // !MHTML
-}
-#endif // WEBARCHIVE || MHTML
-
 void DocumentLoader::commitData(const SharedBuffer& data)
 {
     if (!m_gotFirstByte) {
@@ -1254,21 +1239,9 @@ void DocumentLoader::commitData(const SharedBuffer& data)
             return;
 
 #if ENABLE(WEB_ARCHIVE) || ENABLE(MHTML)
-        if (isLoadingRemoteArchive()) {
-            auto& url { m_archive->mainResource()->url() };
-            if (m_archive->shouldOverrideBaseURL())
-                document.setBaseURLOverride(url);
-#if ENABLE(WEB_ARCHIVE)
-            constexpr auto webArchivePrefix { "webarchive+"_s };
-            if (url.protocol().startsWith(webArchivePrefix)) {
-                auto unprefixedScheme { url.protocol().substring(webArchivePrefix.length()) };
-                if (LegacySchemeRegistry::shouldTreatURLSchemeAsLocal(unprefixedScheme.toStringWithoutCopying()))
-                    document.securityOrigin().grantLoadLocalResources();
-            }
-#endif // WEB_ARCHIVE
-        }
-#endif // WEB_ARCHIVE || MHTML
-
+        if (m_archive && m_archive->shouldOverrideBaseURL())
+            document.setBaseURLOverride(m_archive->mainResource()->url());
+#endif
 #if ENABLE(SERVICE_WORKER)
         if (m_canUseServiceWorkers) {
             if (!document.securityOrigin().isUnique()) {
@@ -1819,7 +1792,12 @@ bool DocumentLoader::scheduleArchiveLoad(ResourceLoader& loader, const ResourceR
     if (!m_archive)
         return false;
 
-    DOCUMENTLOADER_RELEASE_LOG("scheduleArchiveLoad: Failed to unarchive subresource");
+#if ENABLE(WEB_ARCHIVE)
+    // The idea of WebArchiveDebugMode is that we should fail instead of trying to fetch from the network.
+    // Returning true ensures the caller will not try to fetch from the network.
+    if (m_frame->settings().webArchiveDebugModeEnabled() && responseMIMEType() == "application/x-webarchive"_s)
+        return true;
+#endif
 
     // If we want to load from the archive only, then we should always return true so that the caller
     // does not try to fetch from the network.
diff --git a/Source/WebCore/loader/DocumentLoader.h b/Source/WebCore/loader/DocumentLoader.h
index a08220d0fd3c..c7ce40d32b75 100644
--- a/Source/WebCore/loader/DocumentLoader.h
+++ b/Source/WebCore/loader/DocumentLoader.h
@@ -507,10 +507,6 @@ class DocumentLoader
     void clearArchiveResources();
 #endif
 
-#if ENABLE(WEB_ARCHIVE) || ENABLE(MHTML)
-    bool isLoadingRemoteArchive() const;
-#endif
-
     void willSendRequest(ResourceRequest&&, const ResourceResponse&, CompletionHandler<void(ResourceRequest&&)>&&);
     void finishedLoading();
     void mainReceivedError(const ResourceError&);
diff --git a/Source/WebCore/loader/ResourceLoader.cpp b/Source/WebCore/loader/ResourceLoader.cpp
index 61b3a527c6c7..34f3c5c46882 100644
--- a/Source/WebCore/loader/ResourceLoader.cpp
+++ b/Source/WebCore/loader/ResourceLoader.cpp
@@ -222,16 +222,6 @@ void ResourceLoader::start()
 #if ENABLE(WEB_ARCHIVE) || ENABLE(MHTML)
     if (m_documentLoader && m_documentLoader->scheduleArchiveLoad(*this, m_request))
         return;
-
-#if ENABLE(WEB_ARCHIVE)
-    constexpr auto webArchivePrefix { "webarchive+"_s };
-    if (m_request.url().protocol().startsWith(webArchivePrefix)) {
-        auto url { m_request.url() };
-        const auto unprefixedScheme { url.protocol().substring(webArchivePrefix.length()) };
-        url.setProtocol(unprefixedScheme);
-        m_request.setURL(url);
-    }
-#endif
 #endif
 
     if (m_documentLoader && m_documentLoader->applicationCacheHost().maybeLoadResource(*this, m_request, m_request.url()))
diff --git a/Source/WebCore/loader/archive/ArchiveResourceCollection.cpp b/Source/WebCore/loader/archive/ArchiveResourceCollection.cpp
index 286dbb4aca37..24b49875fa5d 100644
--- a/Source/WebCore/loader/archive/ArchiveResourceCollection.cpp
+++ b/Source/WebCore/loader/archive/ArchiveResourceCollection.cpp
@@ -33,10 +33,6 @@
 
 namespace WebCore {
 
-#if ENABLE(WEB_ARCHIVE) && USE(CF)
-constexpr auto webArchivePrefix { "webarchive+"_s };
-#endif
-
 void ArchiveResourceCollection::addAllResources(Archive& archive)
 {
     for (auto& subresource : archive.subresources())
@@ -57,34 +53,19 @@ void ArchiveResourceCollection::addAllResources(Archive& archive)
 // Can we change the design in a manner that will let us deprecate that API without reducing functionality of those apps?
 void ArchiveResourceCollection::addResource(Ref<ArchiveResource>&& resource)
 {
-#if ENABLE(WEB_ARCHIVE) && USE(CF)
-    const bool addPrefix = !resource->url().protocol().startsWith(webArchivePrefix);
-    const auto prefix { addPrefix ? webArchivePrefix : ""_s };
-    const auto subresourceKey { String { prefix + resource->url().string() } };
-#else
-    const auto& subresourceKey = resource->url().string();
-#endif
-    m_subresources.set(subresourceKey, WTFMove(resource));
+    auto& url = resource->url();
+    m_subresources.set(url.string(), WTFMove(resource));
 }
 
-ArchiveResource* ArchiveResourceCollection::archiveResourceForURL(URL url)
+ArchiveResource* ArchiveResourceCollection::archiveResourceForURL(const URL& url)
 {
-#if ENABLE(WEB_ARCHIVE) && USE(CF)
-    const auto httpsScheme = String { webArchivePrefix + "https"_str };
-    const auto httpScheme = String { webArchivePrefix + "http"_str };
-    if (!url.protocol().startsWith(webArchivePrefix))
-        url.setProtocol(String { webArchivePrefix + url.protocol() });
-#else
-    constexpr auto httpsScheme = "https"_s;
-    constexpr auto httpScheme = "http"_s;
-#endif
-
     if (auto* resource = m_subresources.get(url.string()))
         return resource;
-    if (!url.protocolIs(httpsScheme))
+    if (!url.protocolIs("https"_s))
         return nullptr;
-    url.setProtocol(httpScheme);
-    return m_subresources.get(url.string());
+    URL httpURL = url;
+    httpURL.setProtocol("http"_s);
+    return m_subresources.get(httpURL.string());
 }
 
 RefPtr<Archive> ArchiveResourceCollection::popSubframeArchive(const String& frameName, const URL& url)
diff --git a/Source/WebCore/loader/archive/ArchiveResourceCollection.h b/Source/WebCore/loader/archive/ArchiveResourceCollection.h
index 4ccbea08a534..e460b69c2aed 100644
--- a/Source/WebCore/loader/archive/ArchiveResourceCollection.h
+++ b/Source/WebCore/loader/archive/ArchiveResourceCollection.h
@@ -48,7 +48,7 @@ class ArchiveResourceCollection {
     void addResource(Ref<ArchiveResource>&&);
     void addAllResources(Archive&);
     
-    WEBCORE_EXPORT ArchiveResource* archiveResourceForURL(URL);
+    WEBCORE_EXPORT ArchiveResource* archiveResourceForURL(const URL&);
     RefPtr<Archive> popSubframeArchive(const String& frameName, const URL&);
     
 private:    
diff --git a/Source/WebCore/loader/archive/cf/LegacyWebArchive.cpp b/Source/WebCore/loader/archive/cf/LegacyWebArchive.cpp
index 46bb2372d0f1..412c082d4fc6 100644
--- a/Source/WebCore/loader/archive/cf/LegacyWebArchive.cpp
+++ b/Source/WebCore/loader/archive/cf/LegacyWebArchive.cpp
@@ -172,7 +172,7 @@ ResourceResponse LegacyWebArchive::createResourceResponseFromPropertyListData(CF
     return ResourceResponse();
 }
 
-RefPtr<ArchiveResource> LegacyWebArchive::createResource(CFDictionaryRef dictionary, const UsePrefixedScheme usePrefixedScheme)
+RefPtr<ArchiveResource> LegacyWebArchive::createResource(CFDictionaryRef dictionary)
 {
     ASSERT(dictionary);
     if (!dictionary)
@@ -196,16 +196,12 @@ RefPtr<ArchiveResource> LegacyWebArchive::createResource(CFDictionaryRef diction
         return nullptr;
     }
 
-    const auto cfURL = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceURLKey));
-    if (cfURL && CFGetTypeID(cfURL) != CFStringGetTypeID()) {
+    auto url = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceURLKey));
+    if (url && CFGetTypeID(url) != CFStringGetTypeID()) {
         LOG(Archives, "LegacyWebArchive - URL is not of type CFString, cannot create invalid resource");
         return nullptr;
     }
 
-    const String stringURL { cfURL };
-    const auto schemePrefix = usePrefixedScheme == UsePrefixedScheme::Yes ? "webarchive+"_s : ""_s;
-    const URL url { schemePrefix + stringURL };
-
     auto textEncoding = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceTextEncodingNameKey));
     if (textEncoding && CFGetTypeID(textEncoding) != CFStringGetTypeID()) {
         LOG(Archives, "LegacyWebArchive - Text encoding is not of type CFString, cannot create invalid resource");
@@ -229,7 +225,7 @@ RefPtr<ArchiveResource> LegacyWebArchive::createResource(CFDictionaryRef diction
         response = createResourceResponseFromPropertyListData(resourceResponseData, resourceResponseVersion);
     }
 
-    return ArchiveResource::create(SharedBuffer::create(resourceData), url, mimeType, textEncoding, frameName, response);
+    return ArchiveResource::create(SharedBuffer::create(resourceData), URL { url }, mimeType, textEncoding, frameName, response);
 }
 
 Ref<LegacyWebArchive> LegacyWebArchive::create()
@@ -254,15 +250,10 @@ Ref<LegacyWebArchive> LegacyWebArchive::create(Ref<ArchiveResource>&& mainResour
 
 RefPtr<LegacyWebArchive> LegacyWebArchive::create(FragmentedSharedBuffer& data)
 {
-    return create(URL(), data, UsePrefixedScheme::No);
+    return create(URL(), data);
 }
 
 RefPtr<LegacyWebArchive> LegacyWebArchive::create(const URL&, FragmentedSharedBuffer& data)
-{
-    return create(URL(), data, UsePrefixedScheme::Yes);
-}
-
-RefPtr<LegacyWebArchive> LegacyWebArchive::create(const URL&, FragmentedSharedBuffer& data, const UsePrefixedScheme usePrefixedScheme)
 {
     LOG(Archives, "LegacyWebArchive - Creating from raw data");
 
@@ -291,13 +282,13 @@ RefPtr<LegacyWebArchive> LegacyWebArchive::create(const URL&, FragmentedSharedBu
         return nullptr;
     }
 
-    if (!archive->extract(plist.get(), usePrefixedScheme))
+    if (!archive->extract(plist.get()))
         return nullptr;
 
     return WTFMove(archive);
 }
 
-bool LegacyWebArchive::extract(CFDictionaryRef dictionary, const UsePrefixedScheme usePrefixedScheme)
+bool LegacyWebArchive::extract(CFDictionaryRef dictionary)
 {
     ASSERT(dictionary);
     if (!dictionary) {
@@ -315,7 +306,7 @@ bool LegacyWebArchive::extract(CFDictionaryRef dictionary, const UsePrefixedSche
         return false;
     }
 
-    auto mainResource = createResource(mainResourceDict, usePrefixedScheme);
+    auto mainResource = createResource(mainResourceDict);
     if (!mainResource) {
         LOG(Archives, "LegacyWebArchive - Failed to parse main resource from CFDictionary or main resource does not exist, aborting invalid WebArchive");
         return false;
@@ -343,7 +334,7 @@ bool LegacyWebArchive::extract(CFDictionaryRef dictionary, const UsePrefixedSche
                 return false;
             }
 
-            if (auto subresource = createResource(subresourceDict, usePrefixedScheme))
+            if (auto subresource = createResource(subresourceDict))
                 addSubresource(subresource.releaseNonNull());
         }
     }
@@ -364,7 +355,7 @@ bool LegacyWebArchive::extract(CFDictionaryRef dictionary, const UsePrefixedSche
             }
 
             auto subframeArchive = create();
-            if (subframeArchive->extract(subframeDict, usePrefixedScheme))
+            if (subframeArchive->extract(subframeDict))
                 addSubframeArchive(WTFMove(subframeArchive));
             else
                 LOG(Archives, "LegacyWebArchive - Invalid subframe archive skipped");
diff --git a/Source/WebCore/loader/archive/cf/LegacyWebArchive.h b/Source/WebCore/loader/archive/cf/LegacyWebArchive.h
index 4b3238ea6076..5a07b10b4be6 100644
--- a/Source/WebCore/loader/archive/cf/LegacyWebArchive.h
+++ b/Source/WebCore/loader/archive/cf/LegacyWebArchive.h
@@ -52,8 +52,6 @@ class LegacyWebArchive final : public Archive {
     WEBCORE_EXPORT RetainPtr<CFDataRef> rawDataRepresentation();
 
 private:
-    enum class UsePrefixedScheme : bool { No, Yes };
-
     LegacyWebArchive() = default;
 
     bool shouldLoadFromArchiveOnly() const final { return false; }
@@ -63,16 +61,15 @@ class LegacyWebArchive final : public Archive {
 
     enum MainResourceStatus { Subresource, MainResource };
 
-    static RefPtr<LegacyWebArchive> create(const URL&, FragmentedSharedBuffer&, const UsePrefixedScheme);
     static RefPtr<LegacyWebArchive> create(const String& markupString, Frame&, const Vector<Node*>& nodes, Function<bool(Frame&)>&& frameFilter);
-    static RefPtr<ArchiveResource> createResource(CFDictionaryRef, const UsePrefixedScheme);
+    static RefPtr<ArchiveResource> createResource(CFDictionaryRef);
     static ResourceResponse createResourceResponseFromMacArchivedData(CFDataRef);
     static ResourceResponse createResourceResponseFromPropertyListData(CFDataRef, CFStringRef responseDataType);
     static RetainPtr<CFDataRef> createPropertyListRepresentation(const ResourceResponse&);
     static RetainPtr<CFDictionaryRef> createPropertyListRepresentation(Archive&);
     static RetainPtr<CFDictionaryRef> createPropertyListRepresentation(ArchiveResource*, MainResourceStatus);
 
-    bool extract(CFDictionaryRef, const UsePrefixedScheme);
+    bool extract(CFDictionaryRef);
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/page/SecurityOrigin.cpp b/Source/WebCore/page/SecurityOrigin.cpp
index f825bdfb0900..cb3da95edc8b 100644
--- a/Source/WebCore/page/SecurityOrigin.cpp
+++ b/Source/WebCore/page/SecurityOrigin.cpp
@@ -119,11 +119,6 @@ static bool shouldTreatAsUniqueOrigin(const URL& url)
         || url.protocolIs("x-apple-ql-id2"_s)
         || url.protocolIs("x-apple-ql-magic"_s)
 #endif
-#if ENABLE(WEB_ARCHIVE) && USE(CF)
-        || url.protocolIs("webarchive+http"_s)
-        || url.protocolIs("webarchive+https"_s)
-        || url.protocolIs("webarchive+ftp"_s)
-#endif
 #if PLATFORM(GTK) || PLATFORM(WPE)
         || url.protocolIs("resource"_s)
 #if ENABLE(PDFJS)
diff --git a/Source/WebKit/UIProcess/API/C/WKPreferences.cpp b/Source/WebKit/UIProcess/API/C/WKPreferences.cpp
index 4af9465841d7..789fbf5c4bf9 100644
--- a/Source/WebKit/UIProcess/API/C/WKPreferences.cpp
+++ b/Source/WebKit/UIProcess/API/C/WKPreferences.cpp
@@ -555,14 +555,14 @@ bool WKPreferencesGetDOMTimersThrottlingEnabled(WKPreferencesRef preferencesRef)
     return toImpl(preferencesRef)->domTimersThrottlingEnabled();
 }
 
-void WKPreferencesSetWebArchiveTestingModeEnabled(WKPreferencesRef preferencesRef, bool enabled)
+void WKPreferencesSetWebArchiveDebugModeEnabled(WKPreferencesRef preferencesRef, bool enabled)
 {
-    toImpl(preferencesRef)->setWebArchiveTestingModeEnabled(enabled);
+    toImpl(preferencesRef)->setWebArchiveDebugModeEnabled(enabled);
 }
 
-bool WKPreferencesGetWebArchiveTestingModeEnabled(WKPreferencesRef preferencesRef)
+bool WKPreferencesGetWebArchiveDebugModeEnabled(WKPreferencesRef preferencesRef)
 {
-    return toImpl(preferencesRef)->webArchiveTestingModeEnabled();
+    return toImpl(preferencesRef)->webArchiveDebugModeEnabled();
 }
 
 void WKPreferencesSetLocalFileContentSniffingEnabled(WKPreferencesRef preferencesRef, bool enabled)
@@ -2143,15 +2143,6 @@ bool WKPreferencesGetXSSAuditorEnabled(WKPreferencesRef)
     return false;
 }
 
-void WKPreferencesSetWebArchiveDebugModeEnabled(WKPreferencesRef preferencesRef, bool enabled)
-{
-}
-
-bool WKPreferencesGetWebArchiveDebugModeEnabled(WKPreferencesRef preferencesRef)
-{
-    return false;
-}
-
 void WKPreferencesSetJavaEnabled(WKPreferencesRef, bool)
 {
 }
diff --git a/Source/WebKit/UIProcess/API/C/WKPreferencesRefPrivate.h b/Source/WebKit/UIProcess/API/C/WKPreferencesRefPrivate.h
index 6614ea662db1..11be798b5699 100644
--- a/Source/WebKit/UIProcess/API/C/WKPreferencesRefPrivate.h
+++ b/Source/WebKit/UIProcess/API/C/WKPreferencesRefPrivate.h
@@ -124,8 +124,8 @@ WK_EXPORT void WKPreferencesSetDOMTimersThrottlingEnabled(WKPreferencesRef prefe
 WK_EXPORT bool WKPreferencesGetDOMTimersThrottlingEnabled(WKPreferencesRef preferences);
 
 // Defaults to false.
-WK_EXPORT void WKPreferencesSetWebArchiveTestingModeEnabled(WKPreferencesRef preferences, bool enabled);
-WK_EXPORT bool WKPreferencesGetWebArchiveTestingModeEnabled(WKPreferencesRef preferences);
+WK_EXPORT void WKPreferencesSetWebArchiveDebugModeEnabled(WKPreferencesRef preferences, bool enabled);
+WK_EXPORT bool WKPreferencesGetWebArchiveDebugModeEnabled(WKPreferencesRef preferences);
 
 // Defaults to false.
 WK_EXPORT void WKPreferencesSetLocalFileContentSniffingEnabled(WKPreferencesRef preferences, bool enabled);
@@ -563,8 +563,6 @@ WK_EXPORT void WKPreferencesSetResourceTimingEnabled(WKPreferencesRef, bool) WK_
 WK_EXPORT bool WKPreferencesGetResourceTimingEnabled(WKPreferencesRef) WK_C_API_DEPRECATED;
 WK_EXPORT void WKPreferencesSetSubpixelCSSOMElementMetricsEnabled(WKPreferencesRef, bool) WK_C_API_DEPRECATED;
 WK_EXPORT bool WKPreferencesGetSubpixelCSSOMElementMetricsEnabled(WKPreferencesRef) WK_C_API_DEPRECATED;
-WK_EXPORT void WKPreferencesSetWebArchiveDebugModeEnabled(WKPreferencesRef preferences, bool enabled) WK_C_API_DEPRECATED;
-WK_EXPORT bool WKPreferencesGetWebArchiveDebugModeEnabled(WKPreferencesRef preferences) WK_C_API_DEPRECATED;
 
 #ifdef __cplusplus
 }
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKPreferences.mm b/Source/WebKit/UIProcess/API/Cocoa/WKPreferences.mm
index 348f152a759f..3c96e97c4ad7 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKPreferences.mm
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKPreferences.mm
@@ -978,14 +978,14 @@ - (BOOL)_domTimersThrottlingEnabled
     return _preferences->domTimersThrottlingEnabled();
 }
 
-- (void)_setWebArchiveTestingModeEnabled:(BOOL)enabled
+- (void)_setWebArchiveDebugModeEnabled:(BOOL)enabled
 {
-    _preferences->setWebArchiveTestingModeEnabled(enabled);
+    _preferences->setWebArchiveDebugModeEnabled(enabled);
 }
 
-- (BOOL)_webArchiveTestingModeEnabled
+- (BOOL)_webArchiveDebugModeEnabled
 {
-    return _preferences->webArchiveTestingModeEnabled();
+    return _preferences->webArchiveDebugModeEnabled();
 }
 
 - (void)_setLocalFileContentSniffingEnabled:(BOOL)enabled
@@ -1616,15 +1616,6 @@ - (BOOL)_subpixelCSSOMElementMetricsEnabled
     return NO;
 }
 
-- (void)_setWebArchiveDebugModeEnabled:(BOOL)enabled
-{
-}
-
-- (BOOL)_webArchiveDebugModeEnabled
-{
-    return NO;
-}
-
 #endif
 
 #if PLATFORM(MAC)
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKPreferencesPrivate.h b/Source/WebKit/UIProcess/API/Cocoa/WKPreferencesPrivate.h
index 192b8317f596..5df3734a9f01 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKPreferencesPrivate.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKPreferencesPrivate.h
@@ -186,7 +186,7 @@ typedef NS_ENUM(NSInteger, _WKPitchCorrectionAlgorithm) {
 @property (nonatomic, setter=_setDefaultTextEncodingName:) NSString *_defaultTextEncodingName WK_API_AVAILABLE(macos(10.13.4));
 @property (nonatomic, setter=_setAuthorAndUserStylesEnabled:) BOOL _authorAndUserStylesEnabled WK_API_AVAILABLE(macos(10.13.4));
 @property (nonatomic, setter=_setDOMTimersThrottlingEnabled:) BOOL _domTimersThrottlingEnabled WK_API_AVAILABLE(macos(10.13.4));
-@property (nonatomic, setter=_setWebArchiveTestingModeEnabled:) BOOL _webArchiveTestingModeEnabled WK_API_AVAILABLE(macos(13.0));
+@property (nonatomic, setter=_setWebArchiveDebugModeEnabled:) BOOL _webArchiveDebugModeEnabled WK_API_AVAILABLE(macos(10.13.4));
 @property (nonatomic, setter=_setLocalFileContentSniffingEnabled:) BOOL _localFileContentSniffingEnabled WK_API_AVAILABLE(macos(10.13.4));
 @property (nonatomic, setter=_setUsesPageCache:) BOOL _usesPageCache WK_API_AVAILABLE(macos(10.13.4));
 @property (nonatomic, setter=_setPageCacheSupportsPlugins:) BOOL _pageCacheSupportsPlugins WK_API_AVAILABLE(macos(10.13.4));
@@ -231,6 +231,6 @@ typedef NS_ENUM(NSInteger, _WKPitchCorrectionAlgorithm) {
 @property (nonatomic, setter=_setRequestAnimationFrameEnabled:) BOOL _requestAnimationFrameEnabled WK_API_DEPRECATED("requestAnimationFrame is always enabled", macos(10.15.4, 13.0), ios(13.4, 16.0));
 #if !TARGET_OS_IPHONE
 @property (nonatomic, setter=_setSubpixelCSSOMElementMetricsEnabled:) BOOL _subpixelCSSOMElementMetricsEnabled WK_API_DEPRECATED("Subpixel CSSOM element metrics are no longer supported", macos(10.13.4, 10.15));
-@property (nonatomic, setter=_setWebArchiveDebugModeEnabled:) BOOL _webArchiveDebugModeEnabled WK_API_DEPRECATED("WebArchive Debug Mode is no longer supported", macos(10.13.4, 13.0));
 #endif
+
 @end
diff --git a/Source/WebKitLegacy/mac/WebView/WebView.mm b/Source/WebKitLegacy/mac/WebView/WebView.mm
index 894ab525b4af..3f61c2bbc21e 100644
--- a/Source/WebKitLegacy/mac/WebView/WebView.mm
+++ b/Source/WebKitLegacy/mac/WebView/WebView.mm
@@ -3273,13 +3273,6 @@ + (BOOL)_canHandleRequest:(NSURLRequest *)request forMainFrame:(BOOL)forMainFram
     if ([scheme _webkit_isCaseInsensitiveEqualToString:@"blob"])
         return YES;
 
-    NSString* webArchivePrefix = @"webarchive+";
-    if ([scheme _webkit_hasCaseInsensitivePrefix:webArchivePrefix]) {
-        auto url = [request URL];
-        NSString* modifiedURL = [[url absoluteString] substringFromIndex:[webArchivePrefix length]];
-        return [self _canHandleRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:modifiedURL]] forMainFrame:forMainFrame];
-    }
-
     return NO;
 }
 
diff --git a/Tools/TestWebKitAPI/Tests/mac/LoadWebArchive.mm b/Tools/TestWebKitAPI/Tests/mac/LoadWebArchive.mm
index fb39c5b845e6..71102b996ea0 100644
--- a/Tools/TestWebKitAPI/Tests/mac/LoadWebArchive.mm
+++ b/Tools/TestWebKitAPI/Tests/mac/LoadWebArchive.mm
@@ -32,7 +32,6 @@
 #import "TestWKWebView.h"
 #import <WebKit/WKDragDestinationAction.h>
 #import <WebKit/WKNavigationPrivate.h>
-#import <WebKit/WKPreferencesPrivate.h>
 #import <WebKit/WKWebView.h>
 #import <WebKit/WKWebViewConfigurationPrivate.h>
 #import <WebKit/WKWebViewPrivate.h>
@@ -206,9 +205,9 @@ - (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWe
     EXPECT_WK_STREQ(finalURL, "");
 }
 
-static NSData* constructArchive(const char *script)
+static NSData* constructArchive()
 {
-    auto *js = [NSString stringWithUTF8String:script];
+    NSString *js = @"alert('loaded http subresource successfully')";
     auto response = adoptNS([[NSURLResponse alloc] initWithURL:[NSURL URLWithString:@"http://download/script.js"] MIMEType:@"application/javascript" expectedContentLength:js.length textEncodingName:@"utf-8"]);
     auto responseArchiver = adoptNS([[NSKeyedArchiver alloc] initRequiringSecureCoding:YES]);
     [responseArchiver encodeObject:response.get() forKey:@"WebResourceResponse"];
@@ -233,7 +232,7 @@ - (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWe
 
 TEST(LoadWebArchive, HTTPSUpgrade)
 {
-    NSData *data = constructArchive("alert('loaded http subresource successfully')");
+    NSData *data = constructArchive();
 
     auto webView = adoptNS([WKWebView new]);
     [webView loadData:data MIMEType:@"application/x-webarchive" characterEncodingName:@"utf-8" baseURL:[NSURL URLWithString:@"http://download/"]];
@@ -242,7 +241,7 @@ - (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWe
 
 TEST(LoadWebArchive, DisallowedNetworkHosts)
 {
-    NSData *data = constructArchive("alert('loaded http subresource successfully')");
+    NSData *data = constructArchive();
 
     auto configuration = adoptNS([[WKWebViewConfiguration alloc] init]);
     configuration.get()._allowedNetworkHosts = [NSSet set];
@@ -253,7 +252,3 @@ - (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWe
 }
 
 } // namespace TestWebKitAPI
-
-#if USE(APPLE_INTERNAL_SDK)
-#import <WebKitAdditions/LoadWebArchiveAdditions.mm>
-#endif