Explore the integration of web technologies within your app. Discuss building web-based apps, leveraging Safari functionalities, and integrating with web services.

Learn more
All subtopics
Posts under Safari & Web topic

Post

Replies

Boosts

Views

Activity

macOS 26 beta 4 and iOS 26 beta 4 - WebKit XML parser crashes parsing XHTML with namespaces
Our app, VitalSource Bookshelf, is an EPUB reader that uses a WKWebView to display book content. The EPUB content format is XHTML and uses namespaces (for the epub:type declaration). On beta 4, the webkit process repeatedly crashes when loading our content. The crash appears to be in the XML parser. Here's what's at the top of the stack trace: 0 WebCore 0x19166a878 WebCore::XMLDocumentParser::startElementNs(unsigned char const*, unsigned char const*, unsigned char const*, int, unsigned char const**, int, int, unsigned char const**) + 4968 1 libxml2.2.dylib 0x19c5a2bd0 xmlParseStartTag2 + 3940 2 libxml2.2.dylib 0x19c59e730 xmlParseTryOrFinish + 2984 3 libxml2.2.dylib 0x19c59d8e4 xmlParseChunk + 708 4 WebCore 0x191668ec8 WebCore::XMLDocumentParser::doWrite(WTF::String const&) + 636 5 WebCore 0x191665b78 WebCore::XMLDocumentParser::append(WTF::RefPtr<WTF::StringImpl, WTF::RawPtrTraits<WTF::StringImpl>, WTF::DefaultRefDerefTraits<WTF::StringImpl>>&&) + 304 6 WebCore 0x190105db0 WebCore::DecodedDataDocumentParser::appendBytes(WebCore::DocumentWriter&, std::__1::span<unsigned char const, 18446744073709551615ul>) + 268 7 WebCore 0x190861c3c WebCore::DocumentLoader::commitData(WebCore::SharedBuffer const&) + 1488 8 WebKit 0x18e07ca3c WebKit::WebLocalFrameLoaderClient::committedLoad(WebCore::DocumentLoader*, WebCore::SharedBuffer const&) + 52 9 WebCore 0x190869db4 WebCore::DocumentLoader::commitLoad(WebCore::SharedBuffer const&) + 228 10 WebCore 0x1909521e4 WebCore::CachedRawResource::notifyClientsDataWasReceived(WebCore::SharedBuffer const&) + 268 I was able to reproduce this in Safari on beta 4 just by opening the following trivial xhtml file from the file system - it does the same thing it does in our app, which is reloads and crashes several times, followed by the "A problem repeatedly occurred with..." error message. <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops" epub:prefix="vst: http://vitalsource.com/"><head></head><body class="dash" epub:type="chapter" data-begin-o="0" data-begin-o2="0" data-begin-o3="0" data-o="0" id="eid1844" data-end-o="14703" data-end-o2="14703" data-end-o3="14703"><h2 class="title" data-o="0" id="eid1845" data-out="33"><span class="label" data-o="0" id="eid1846"><span class="label-inner"><b data-o="0" id="eid1847">CHAPTER X</b> </span></span>THE SUBMARINE COAL-MINES</h2></body></html> I've also filed a feedback. But posting here just to raise the visibility - this is critical for us. I think it was introduced in beta 4; that's at least when we first noticed it. It was working in the earlier betas, I just don't remember if I tried beta 3 or not. It happens on iOS, macOS, and iPadOS. This has never been a problem in any earlier release of macOS / iOS.
Topic: Safari & Web SubTopic: General
3
1
513
Aug ’25
How do I add a UI to a Safari Web Extension?
I have a Safari Web Extension that successfully receives a message from a webpage and returns a response. I now want to add a user interface to the Safari Web Extension. How do I do this? I have modified the default template code as follow to add an NSAlert for testing. The modal runs, but no alert ever appears, and the code remains stuck at runModal. What is the correct way to add a UI to a webextension? - (void)beginRequestWithExtensionContext:(NSExtensionContext *)context {     id message = [context.inputItems.firstObject userInfo][SFExtensionMessageKey];     NSLog(@"Received message from browser.runtime.sendNativeMessage: %@", message);     NSAlert* alert = [[NSAlert alloc]init];     [alert setMessageText:message[@"request"]];     [alert setInformativeText:@"Hello"];     [alert runModal];     NSExtensionItem *response = [[NSExtensionItem alloc] init];     response.userInfo = @{ SFExtensionMessageKey: @{ @"id": message[@"id"], @"uuid": message[@"uuid"], @"contentType": message[@"contentType"], @"response": message[@"request"] } };     [context completeRequestReturningItems:@[ response ] completionHandler:nil]; } @end
Topic: Safari & Web SubTopic: General Tags:
3
0
1.2k
Mar ’25
Enable a Developer ID-signed and notarised extension without enabling "allow unsigned extension"
Hello, According to the documentation: If you provide your extension in macOS and don’t want to use the Mac App Store for distribution, you can sign and notarize your extension’s app with a Developer ID to distribute it outside the Mac App Store. However, I found this to be untrue in practice. Even after signing and notarising the Safari extension correctly, it is not possible to enable it in Safari without turning on "allow unsigned extension". This makes it impossible to distribute your Developer ID–signed and notarized extension outside the Mac App Store. I would like to distribute my web extension directly to employees in my organization using MDM without having each user manually enable "allow unsigned extension" for it to work. Any way to make it work? The documentation is quite confusing in this aspect, it says "Safari only supports signed extensions" but my extension is rejected even if notarised and signed.
Topic: Safari & Web SubTopic: General Tags:
3
0
166
Apr ’25
Request for Native AJAX API Request Interception Support in WKWebView
Hello WebKit Team, I’m writing to ask if iOS provides a native way to intercept AJAX (XMLHttpRequest or fetch) calls inside WKWebView. On Android, this is handled via: shouldInterceptRequest(WebView view, WebResourceRequest request) but iOS currently seems to have no equivalent. We’ve tried: WKURLSchemeHandler → works only for custom schemes URLProtocol with WKProcessPool → unreliable for AJAX in WebView JavaScript injection → partial and unofficial Could you please clarify: Is there a recommended native approach to intercept AJAX requests? If not supported, is it planned for future releases? Any official workaround or guidance? This is critical for debugging, analytics, and compliance in hybrid apps.
Topic: Safari & Web SubTopic: General Tags:
3
0
970
Dec ’25
PWA video playback stopped working after updating iOS to 26.0.1
Hey Guys My PWA video playback and even youtube videos stopped working after updating iOS to 26.0.1. The video thumnails appear fine and if i try to play the video, it remains stuck. If i restart the phone, the video plays for a second in the PWA and then stops again and entire app gets stuck. Request apple team to fix this issue at the earliest. This is hampering all my iOS users who install the PWA on their device homescreen and use it as app. FYI strangely EVERYTHING WORKS FINE ON iOS SAFARI browser including videos playback If i open it as a web app. so this seems like a specific PWA issue on latest ios 26.0.1
Topic: Safari & Web SubTopic: General
3
2
596
Nov ’25
header and footer positions shifted in Safari tab settings
Thank you for supporting me. My environment Device: iPhone 15 Pro OS: iOS 26.0 Public Beta (23A5336a) In iOS 26, three types of tabs were added to Safari. Depending on the option, the behavior of the fixed header and footer can be unstable. *Tab settings can be changed in the iOS Settings app under "Apps -> Safari" > "Tabs." The following behavior differs depending on the tab. Compact When scrolling down, the header and footer shift up by a few pixels. A margin is created between the footer and the URL input field. Bottom Behaves the same as "Compact." Top The header is completely hidden below the URL input field at the top of the screen, leaving a margin below the footer. Below is the sample code to check the operation. <!doctype html> <html lang="ja"> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width,initial-scale=1" /> <title>固定ヘッダー/フッター + モーダル</title> <style> :root { --header-h: 56px; --footer-h: 56px; } body { margin: 0; font-family: sans-serif; line-height: 1.6; background: #f9fafb; padding-top: var(--header-h); padding-bottom: var(--footer-h); } header .inner, footer .inner { width: 100%; max-width: var(--max-content-w); padding: 0 16px; display: flex; align-items: center; justify-content: space-between; } header, footer { position: fixed; left: 0; right: 0; display: flex; align-items: center; justify-content: center; z-index: 100; background: #fff; } header { top: 0; height: var(--header-h); border-bottom: 1px solid #ddd; } footer { bottom: 0; height: var(--footer-h); border-top: 1px solid #ddd; } main { padding: 16px; } .btn { padding: 8px 16px; border: 1px solid #2563eb; background: #2563eb; color: #fff; border-radius: 6px; cursor: pointer; } /* モーダル関連 */ .modal { position: fixed; inset: 0; display: none; z-index: 1000; } .modal.is-open { display: block; } .modal__backdrop { position: absolute; inset: 0; background: rgba(0,0,0,0.5); } .modal__panel { position: relative; max-width: 600px; margin: 10% auto; background: #fff; border-radius: 8px; padding: 20px; z-index: 1; } .modal__head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; } .modal__title { margin: 0; font-size: 18px; font-weight: bold; } .modal__close { background: none; border: none; font-size: 20px; cursor: pointer; } </style> </head> <body> <header> <div class="inner"> <h1>デモページ</h1> <button id="openModal" class="btn">モーダルを開く</button> </div> </header> <main class="container" id="main"> <h2>スクロール用の適当なコンテンツ1</h2> <p>ヘッダーとフッターは常に表示されます。モーダルボタンを押すと、画面いっぱいのダイアログが開きます。</p> <!-- ダミーカードを複数 --> <section class="grid"> <div class="card"><strong>カード1</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード2</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード3</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード4</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード5</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード6</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード7</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード8</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード9</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード10</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> </section> </main> <footer> <small>&copy; 2025 Demo</small> </footer> <!-- モーダル --> <div class="modal" id="modal"> <div class="modal__backdrop"></div> <div class="modal__panel"> <div class="modal__head"> <h2 class="modal__title">モーダル</h2> <button class="modal__close" id="closeModal">&times;</button> </div> <p>これは白いビューのモーダルです。背景は黒く半透明で覆われています。</p> </div> </div> <script> const modal = document.getElementById('modal'); const openBtn = document.getElementById('openModal'); const closeBtn = document.getElementById('closeModal'); const backdrop = modal.querySelector('.modal__backdrop'); openBtn.addEventListener('click', () => { modal.classList.add('is-open'); }); function closeModal() { modal.classList.remove('is-open'); } closeBtn.addEventListener('click', closeModal); backdrop.addEventListener('click', closeModal); window.addEventListener('keydown', (e) => { if (e.key === 'Escape' && modal.classList.contains('is-open')) { closeModal(); } }); </script> </body> </html>
Topic: Safari & Web SubTopic: General Tags:
3
0
829
Sep ’25
Accessing WKNavigationAction.sourceFrame.request crashes
Hi all, I'm currently working with WKWebView and implementing the WKNavigationDelegate protocol. In particular, I'm trying to inspect the sourceFrame of a WKNavigationAction to make navigation policy decisions based on the frame's URL path. Here's the relevant Swift code inside decidePolicyFor: public func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, preferences: WKWebpagePreferences, decisionHandler: @escaping (WKNavigationActionPolicy, WKWebpagePreferences) -> Void) { // ... let sourceFrame: WKFrameInfo = navigationAction.sourceFrame let request: URLRequest = sourceFrame.request // <- SIGABRT occurs here // ... } The issue is that the app crashes with a SIGABRT at runtime when attempting to access sourceFrame.request. According to Swift's type system, neither sourceFrame nor its request property are optional, so at first glance this seems safe. However, the crash report suggests otherwise. From the crash log, it appears that the issue arises during the bridging from Objective-C to Swift: Thread 1 Queue : com.apple.main-thread (serial) #0 0x00000001a127a030 in static Foundation.URLRequest._unconditionallyBridgeFromObjectiveC(Swift.Optional<__C.NSURLRequest>) -> Foundation.URLRequest () #1 0x00000001056c48b0 in CustomWebViewController.webView(_:decidePolicyFor:preferences:decisionHandler:) #2 0x00000001056c4c78 in @objc CustomWebViewController.webView(_:decidePolicyFor:preferences:decisionHandler:) () #3 0x00000001b8c66e0c in WebKit::NavigationState::NavigationClient::decidePolicyForNavigationAction () #4 0x00000001b8fd14dc in WebKit::WebPageProxy::decidePolicyForNavigationAction () #5 0x00000001b8fcfc7c in WebKit::WebPageProxy::decidePolicyForNavigationActionAsyncShared () #6 0x00000001b8fcfb18 in WebKit::WebPageProxy::decidePolicyForNavigationActionAsync () #7 0x00000001b87ddaa0 in WebKit::WebPageProxy::didReceiveMessage () #8 0x00000001b869f474 in IPC::MessageReceiverMap::dispatchMessage () #9 0x00000001b878dda4 in WebKit::WebProcessProxy::dispatchMessage () #10 0x00000001b878d614 in WebKit::WebProcessProxy::didReceiveMessage () #11 0x00000001b869e7e4 in IPC::Connection::dispatchMessage () #12 0x00000001b869e358 in IPC::Connection::dispatchIncomingMessages () #13 0x00000001b9a96a44 in WTF::RunLoop::performWork () #14 0x00000001b9a96688 in WTF::RunLoop::performWork () #15 0x00000001a2428b9c in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ () #16 0x00000001a24289b4 in __CFRunLoopDoSource0 () #17 0x00000001a2428810 in __CFRunLoopDoSources0 () #18 0x00000001a2429190 in __CFRunLoopRun () #19 0x00000001a242ad4c in CFRunLoopRunSpecific () #20 0x00000001ef705454 in GSEventRunModal () #21 0x00000001a4e45890 in -[UIApplication _run] () #22 0x00000001a4e10cec in UIApplicationMain () #23 0x00000001a4ef261c in ___lldb_unnamed_symbol275689 () #24 0x00000001059a5104 in static UIApplicationDelegate.main() () #25 0x00000001059a5074 in static AppDelegate.$main() () #26 0x00000001059a82ec in main () #27 0x00000001c940af0c in start () This implies that while Swift treats sourceFrame.request as non-optional, the underlying Objective-C implementation may actually return nil—leading to a crash when the non-optional Swift type attempts to force unwrap it. My question: Is there a way to safely access navigationAction.sourceFrame.request —- or determine if it’s nil—before Swift attempts the implicit bridging from Objective-C? Or is there an established workaround for safely inspecting this property? Any guidance or best practices for avoiding this crash would be greatly appreciated! Thanks in advance.
Topic: Safari & Web SubTopic: General Tags:
3
0
135
Apr ’25
IOS 26, web extensions no longer available
I recently upgraded my device from IOS 18.4 to IOS 26. My web extension has disapeared from safari. I can see it in Settings > Apps > Safari > Extensions and when I turn it on and re-open safari. I just get a mesasge that says "{extension name} is no longer avaiable". I have tried Manifest V2 and Manifest V3 both yield the same results. The current production extension bundled with the IOS app has the same problem. I can no longer use or test my own extension !? Help please !
Topic: Safari & Web SubTopic: General Tags:
3
1
537
Jul ’25
WKNavigationActionPolicy of "cancel" prints stack trace to console
Starting in iOS 26 (tested on 26.1), when I use any of the “policy” methods of WKNavigationDelegate to return an action policy of cancel I get a trace like this printed to console: 1 0x18de71bbc WebKit::WebFramePolicyListenerProxy::ignore(WebKit::WasNavigationIntercepted) 2 0x18db3dd50 WebKit::NavigationState::NavigationClient::decidePolicyForNavigationAction(WebKit::WebPageProxy&, WTF::Ref<API::NavigationAction, WTF::RawPtrTraits<API::NavigationAction>, WTF::DefaultRefDerefTraits<API::NavigationAction>>&&, WTF::Ref<WebKit::WebFramePolicyListenerProxy, WTF::RawPtrTraits<WebKit::WebFramePolicyListenerProxy>, WTF::DefaultRefDerefTraits<WebKit::WebFramePolicyListenerProxy>>&&)::$_0::operator()(WKNavigationActionPolicy, WKWebpagePreferences*) 3 0x100189e5c $sSo24WKNavigationActionPolicyVIeyBhy_ABIeghy_TR 4 0x100189d38 $s16WebkitPolicyTrap14ViewControllerC03webD0_06decideB3For15decisionHandlerySo05WKWebD0C_So18WKNavigationActionCySo0lmB0VctF 5 0x100189df4 $s16WebkitPolicyTrap14ViewControllerC03webD0_06decideB3For15decisionHandlerySo05WKWebD0C_So18WKNavigationActionCySo0lmB0VctFTo 6 0x18db255c0 WebKit::NavigationState::NavigationClient::decidePolicyForNavigationAction(WebKit::WebPageProxy&, WTF::Ref<API::NavigationAction, WTF::RawPtrTraits<API::NavigationAction>, WTF::DefaultRefDerefTraits<API::NavigationAction>>&&, WTF::Ref<WebKit::WebFramePolicyListenerProxy, WTF::RawPtrTraits<WebKit::WebFramePolicyListenerProxy>, WTF::DefaultRefDerefTraits<WebKit::WebFramePolicyListenerProxy>>&&) 7 0x18dea9848 WebKit::WebPageProxy::decidePolicyForNavigationAction(WTF::Ref<WebKit::WebProcessProxy, WTF::RawPtrTraits<WebKit::WebProcessProxy>, WTF::DefaultRefDerefTraits<WebKit::WebProcessProxy>>&&, WebKit::WebFrameProxy&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&) 8 0x18dea7a34 WebKit::WebPageProxy::decidePolicyForNavigationActionAsync(IPC::Connection&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&) 9 0x18d9cbbf4 void IPC::handleMessageAsync<Messages::WebPageProxy::DecidePolicyForNavigationActionAsync, IPC::Connection, WebKit::WebPageProxy, WebKit::WebPageProxy, void (IPC::Connection&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&)>(IPC::Connection&, IPC::Decoder&, WebKit::WebPageProxy*, void (WebKit::WebPageProxy::*)(IPC::Connection&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&)) 10 0x18d9c7728 WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 11 0x18e49a0d8 IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) 12 0x18df1908c WebKit::WebProcessProxy::dispatchMessage(IPC::Connection&, IPC::Decoder&) 13 0x18d9dfc28 WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 14 0x18e47f72c IPC::Connection::dispatchMessage(WTF::UniqueRef<IPC::Decoder>) 15 0x18e47fac4 IPC::Connection::dispatchIncomingMessages() 16 0x199ad3758 WTF::RunLoop::performWork() 17 0x199ad4eb0 WTF::RunLoop::performWork(void*) 18 0x1804563a4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ 19 0x1804562ec __CFRunLoopDoSource0 20 0x180455a78 __CFRunLoopDoSources0 21 0x180454c4c __CFRunLoopRun 22 0x18044fcec _CFRunLoopRunSpecificWithOptions 23 0x1926be9bc GSEventRunModal 24 0x18630f0d8 -[UIApplication _run] 25 0x186313300 UIApplicationMain 26 0x18554ac38 block_destroy_helper.15 27 0x10018a70c $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ 28 0x10018a67c $s16WebkitPolicyTrap11AppDelegateC5$mainyyFZ 29 0x10018a818 __debug_main_executable_dylib_entry_point 30 0x1000cd3d0 29 dyld 0x00000001000cd3d0 start_sim + 20 31 0x1002bab98 30 ??? 0x00000001002bab98 0x0 + 4297829272 This doesn’t happen in 18.6. Also, it doesn’t seem to have any negative consequences other than the console spam? But then, the navigation is being cancelled anyway, so maybe it’s trapping and just happens to have the effect of not loading the request? Anyway, I guess I can’t upload zips. But it’s pretty easy to reproduce. Just assign a WKWebView a navigationDelegate with an implementation like: func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping @MainActor (WKNavigationActionPolicy) -> Void) { decisionHandler(.cancel) } and then have it .load() anything. Have I been doing this wrong and 26 exposes it? Or is this a bug in 26? If the latter, any downstream consequences I should be looking out for? macOS 15.7.1 (24G231) Xcode 26.1.1 (17B100) iOS 26.1 (23B86)
Topic: Safari & Web SubTopic: General Tags:
3
0
1.1k
Dec ’25
Unable to debug with console.log in Safari on iOS 16.4 Simulator.
I'm working on a regular website, in which I'm trying to debug using the (MacOS) Safari Development tools. Since updating my Simulator to iOS 16.4, console.log is no longer displayed in the Console. Even when executing it directly in the console (console.log('test');), it's not printed. Now, I've read that this is a feature for debugging in-app browser content (https://webkit.org/blog/13936/enabling-the-inspection-of-web-content-in-apps/) but can't find the regular web workaround here. TL;DR: No longer see console.log in iOS 16.4 Safari when debugging from my Mac. Thanks in advance for your suggestions!
Topic: Safari & Web SubTopic: General Tags:
3
6
4.1k
Oct ’25
@@extension_id replacement in CSS file fails in Sequoia, Safari 18
Typically, you can use the @@extension_id special string to reference the absolute path into the bundled resources of an extension, such as an image or a custom font, in a CSS file. However, this broke with Safari 18. Consider this section in a popup.css file: .card-icon { height: 16px; width: 20px; background-image: url(safari-web-extension://__MSG_@@extension_id__/images/card.svg); background-size: 20px 16px; } In Safari 17.4, once loaded in the browser, @@extension_id is replaced with E8BEA491-9B80-45DB-8B20-3E586473BD47, and the background-image reads as so: background-image: url(safari-web-extension://E8BEA491-9B80-45DB-8B20-3E586473BD47/images/card.svg); But as of Safari 18, the @@extension_id just collapses to an empty string, and the background-image reads as so: background-image: url(safari-web-extension:///images/card.svg); and the svg fails to load with the following error: "Failed to load resource: You do not have permission to access the requested resource." This is a regression, does to match the behavior of the other major browsers, and should be fixed. Filed with Feedback ID: FB15104807
Topic: Safari & Web SubTopic: General Tags:
3
1
860
Apr ’25
JavascriptCore crashes with pas_reallocation_did_fail
Hi, My app is using JavascriptCore to run the business logic in a javascript environment. We are randomly seeing crashes when users move the app back to the foreground. These crashes are reported by Firebase (I am attaching an example). I also tried to find them in Organizer, but the stacktraces don't match and I am not sure if they are pointing to the same error (I attach one just in case). I was trying to investigate a little bit about this, but I could find any explanation about what pas_reallocation_did_fail would mean. Here is our implementation: -(void) enqueueCallback:(JSValue *)callback withArguments:(NSArray *)args exclusive:(BOOL)exclusive { [self enqueueBlock:^{ @autoreleasepool { [callback callWithArguments:args]; } } exclusive:exclusive]; } Basically, every JS block is enqueued and then run by a dedicated thread specific to our JSContext. Can I get some help? Thanks in advance! Crashlytics.txt 2024-08-30_10-00-01.2572_-0400-f757f8306eda9679ec1b2ff90fbc66c4eb1fbee7.crash
Topic: Safari & Web SubTopic: General Tags:
3
0
589
Jul ’25
Safe areas ignored after navigating a WebView/WebPage back in a NavigationStack
I'm using the new iOS 26 WebPage/WebView for SwiftUI in a NavigationStack. The initial load works as expected, but when loading items from the back/forward lists, the content jumps beneath the navigation bar: struct WebPageTestView: View { var webPage = WebPage() var body: some View { NavigationStack { WebView(webPage) .toolbar { Button("Back") { if let backItem = webPage.backForwardList.backList.last { webPage.load(backItem) } } Button("Forward") { if let forwardItem = webPage.backForwardList.forwardList.first { webPage.load(forwardItem) } } } } .task { webPage.isInspectable = true webPage.load(URL(string: "https://domchristie.co.uk/")) } } } I have run this on the iOS 26.0 and 26.1 Simulators and get the same issue. The demo website does not use any JavaScript. I was able to replicate this behaviour using a wrapped WKWebView and calling the .ignoresSafeArea(.all) modifier.
Topic: Safari & Web SubTopic: General Tags:
3
1
552
Oct ’25
Tab onDetached and Tab onAttached web extension events are no longer generated in macOS 15.4 / Safari 18.4
Hello - we have a Mac application that uses a browser extension and the web extension JS APIs to communicate with Safari. As of macOS 15.4 / Safari 18.4 the tab OnAttached and tab onDetached events are no longer received. After some testing we verified that the events were working properly as of macOS 15.3 / Safari 18.3 but appear to have been broken in macOS 15.4. Note a similar issue was reported previously for Safari 17.6 and was fixed in macOS 15.0 (FB14324177). We have made a TestFlight version of our app (Tabby) available to simplify debugging via https://testflight.apple.com/join/Va8Zdv9d. To reproduce the issue: Install the Tabby TestFlight build on macOS 15.4 or 15.4.1 Open Safari, go to Safari settings and select the Extensions tab Enable the Tabby extension and grant permissions to all windows all the time Open a Safari window with at least 3 tabs Note the open window and tabs displayed in Tabby In Safari, perform a tab detach by dragging a tab out of the window Expected behavior Within Safari the detached tab should now be in it’s own window, and via the onDetached event Tabby should update to show the tab in it’s own window AND removed from the original window. Observed Safari fails to send the onDetached event and Tabby will continue to display the detached tab in its original window in addition to the new window. You can also use the repro steps above to observe the onDetached event being received or not by Tabby in the Safari developer console. The same steps but re-attaching the tab to the original window can be used to observe the onAttached event being received or not. We’ve attached two screen recordings to the Feedback ID below, one showing the events working on macOS 15.3, and one showing the events failing to be received on macOS 15.4.1. Note it also fails on macOS 15.4. FEEDBACK ID: FB17367977
Topic: Safari & Web SubTopic: General Tags:
3
0
147
May ’25
guard let result = try? await evaluateJavaScript Crash
myCode is here // titleScript = "document.querySelector('#\(rawValue) span')?.textContent" guard let titleResult = try? await webView.evaluateJavaScript(type.titleScript), let title = titleResult as? String else { return } this code has error Thread 1: Swift runtime failure: Unexpectedly found nil while implicitly unwrapping an Optional value but edit Code like this It is works Successful do { ... let titleResult = try await webView.evaluateJavaScript(type.titleScript) let title = titleResult as? String ... } catch { LogManager.log(level: .error, self, #function, error, "title is Invalid : \(type.titleScript)") continue } I don't know why guard let _ = try? is Fail
Topic: Safari & Web SubTopic: General Tags:
3
0
155
May ’25
Strange reload behavior, WKWebView reloads with returnCacheDataElseLoad after background
Hi, in our app we have a WKWebView with complex web content that is loaded with cachePolicy: .reloadIgnoringLocalCacheData. If the app is in the background for several hours and returns in the foreground we noticed that the system reloads the webpage, but it does so with a cachePoliy returnCacheDataElseLoad. This could break the app if older cache content is present. To reproduce start an app in the simulator (tested with iOS 17.2), put it in the background and via activity monitor stop the processes com.apple.Webkit.WebContent com.apple.Webkit.networking After foreground the reload will happen. Two questions: why is this reload happening after some hours in the background? We haven't seen any crash reports related to this. It mostly happens on one of our test devices (iphone13 with iOS17.2.1). why is the webview reloading with a modified cachePolicy (returnCacheDataElseLoad)? Our temporary fix is to detect this case in "webView:decidePolicyFor navigationAction decisionHandler", cancel the request and reload with modified cachePolicy. Any ideas? Thanks, Heiko Sample code: class ViewController: UIViewController, WKNavigationDelegate, WKUIDelegate { var webView: WKWebView! override func viewDidLoad() { super.viewDidLoad() let config = WKWebViewConfiguration() webView = WKWebView(frame: .zero, configuration: config) webView.uiDelegate = self webView.navigationDelegate = self view.addSubview(webView) let myRequest = URLRequest(url: URL(string: "https://www.apple.com")!, cachePolicy: .reloadIgnoringLocalCacheData) print("request \(myRequest)") webView.load(myRequest) } func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) { print("start loading \(String(describing: navigationAction.request.url)), cache:\(navigationAction.request.cachePolicy)") decisionHandler(.allow) } override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() let fullscreen = CGRect.init(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height) webView.frame = fullscreen } }
Topic: Safari & Web SubTopic: General Tags:
3
1
1.8k
Mar ’25
WKBrowsingContextController is invalid
Is this code invalid on a phone running xcode16 iOS18? Class cls = NSClassFromString(@"WKBrowsingContextController"); SEL sel = NSSelectorFromString(@"registerSchemeForCustomProtocol:"); if ([(id)cls respondsToSelector:sel]) { [(id)cls performSelector:sel withObject:@"http"]; [(id)cls performSelector:sel withObject:@"https"]; } }
Topic: Safari & Web SubTopic: General
3
0
146
Jun ’25
browser.runtime.onMessage in content script intermittently fails on iOS 18.5 (Safari Web Extensions)
Hi everyone, I’m encountering a critical reliability issue with message passing in my Safari Web Extension on iOS 18.4.1 and iOS 18.5. In my extension, I’m using the standard messaging API. The background script sends a message to the content script using browser.tabs.sendMessage(...), and the content script registers a listener via: browser.runtime.onMessage.addListener(handler); This setup has been working reliably in all prior versions of iOS. However, after updating to iOS 18.4.1 and 18.5, I’ve noticed the following behavior: ✅ The content script is successfully injected, and onMessage.addListener is registered (I see logging confirming this). ✅ The background script sends the message using the correct tabId (also confirmed via logs). ❌ The content script’s onMessage listener is not consistently triggered. ⚠️ This issue is intermittent, sometimes the message is received, sometimes it is silently dropped. ❌ No exceptions or errors are thrown in either script, the message appears to be sent, but not picked up from the content script message listener.
Topic: Safari & Web SubTopic: General Tags:
3
3
280
Jul ’25
Cannot Play mp3 File via AudioContext in iOS 18 Safari
I have a Safari extension that plays audio via the javascript AudioContext API. It was working fine under iOS 17 and is now broken under iOS 18. It does not play audio at all. I've tried in both the iOS 18 public beta and the iOS 18.1 developer beta. It is broken in both of them. I've also created Feedback item FB15170620 which has a url attached to a page I created which demonstrates the issue.
Topic: Safari & Web SubTopic: General Tags:
2
0
836
May ’25