Hello, We’ve been using the CesiumJS WebGL library for several years, both on our website and within embedded WebViews in our iOS application. Since upgrading to iOS versions 18.2 and 18.3, we’ve started receiving numerous user complaints regarding application crashes on various iPad and iPhone models when loading CesiumJS. The crashes occur as soon as the 3D view initializes, and the error consistently reported is: "WebGL context lost" This issue appears to be a WebGL-related crash potentially triggered by GPU memory handling or allocation limits. However, we are not detecting any abnormal memory consumption prior to the crash, and the same setup works perfect on older iOS versions and on all Android devices and versions. Steps to Reproduce: Open: https://www.flightradar24.com/30.47,-94.84/8 Click on any aircraft icon on the map. In the aircraft details panel at the bottom, click on the “3D view” tab. On iOS 18.2 or 18.3, the page will crash shortly after initializing CesiumJS WebGL. Affected Devices: This issue is occurring across a wide range of devices, including: iPad 9th Generation iPad Pro (11-inch, 2nd Gen) iPhone SE (2020 and 2022) iPhone 11, 11 Pro iPhone XR iPhone Mini All of the above are running iOS 18.2 or 18.3. The problem does not occur on Android or previous iOS versions. Request: Has anyone else encountered similar issues with WebGL context loss after upgrading to iOS 18.2 or 18.3? Are there any known changes in memory limits or WebGL behavior in these recent iOS updates? We’d appreciate any insight or suggestions on workarounds or potential fixes. Thank you!

Hi, Our company has an application uses the WKWebview to host a lot of content. The content is web based and hosts a lot of charts and metrics. Because of the high content, we've seen the memory of the WebContent hit above 1.25 GB. When that happens, it'll eventually terminate and we have our recovery code to reload the same page Seems like the limit is hidden / internal. Some Apple devs also noted something might be hard coded to be limited as well. Yes, we have our optimizations but we still need to keep our queries, use react, cache, etc... It's just a heavy web application. Request: Can you help us raise that limit? Are there some limitations in Webkit for such a need to terminate? As some devices have much higher RAM than before, we were hoping to be able to dynamically adjust the limit for the wkwebview before it resets. We contacted our internal contacts but they said to post here.

After updating to the new iOS, in Safari, my overlays and backdrops using 100dvh no longer cover the full screen there's now a gap at the bottom. Switching to 100vh fixes it, but that causes scrolling issues on older Safari versions since 100vh includes extra height. Has anyone else experienced this? What's the recommended fix that works across iOS versions?

Hey there. I recently completed an Apple Pay (on the web) integration and it has been working fine, for the most part. I had one customer contact us saying that it didn't work on his devices though. I checked it out, and while it does normally work (and we've had over a thousand transactions use it) there does seem to be some scenarios where it fails and I'm not sure why. I was able to replicate his issue (or at least an issue) by using BrowserStack. When I click the button which should initiate the payment, everything works in the JS code until it gets to the applePaySession.begin() function call. Once it hits that, it just stops. No errors are generated and no notice is given that anything is wrong until you try to do it a second time. Then an error about a payment session already being active on the page is thrown. I'm not really sure how to troubleshoot this since I know it works on my old iPad Air 2, my current M4 Macbook, multiple other devices, and also works when scanning the QR code for use on an iPhone. There is some very specific thing with some very specific versions of Safari that seem to be tripping it up. If it helps, the version of Safari on the BrowserStack device is 18.1, but the version on my Macbook is 18.1.1. The version the customer who is having the issue is on is 18.2 according to him. The customer also says they have used ApplePay on other websites with no issues. I checked one of them and they appear to be using a PayPal integration, where as I am using the ApplePay SDK straight from Apple. There are quite a few variables at play here, and I'm just trying to narrow down what I should be looking at. If one person is reporting the issue, there are probably others with it as well.

We have a JavaScript api that queries our Secure Browser to get the network information – signal strength, network name, plugged in/wifi. Everything worked fine through the Tahoe betas, still does. Now we are getting on the network name and this is breaking our UI. Was this an intentional change or a bug? The other two properties still appear to be working. And it works in all lower MacOS versions. We are currently obtaining it through AppleScript try   set ssid to do shell script "system_profiler SPAirPortDataType | awk '/Current Network Information:/ {getline; sub(/^ +/, ""); sub(/:$/, ""); print}'"   if ssid is equal to "" then     return "Not connected to any Wi-Fi network."   else     return ssid   end if on error errMsg   return "Error: " & errMsg end try

I want to print the content of a WKWebView. I've done some searching, and many people have struggled with this over the years. Some claimed success, but their solutions don't work for me. One person created images for each pages and printed that, but then if you were to print to PDF, you'd get a PDF containing images rather than text. If I just call the printView(_:)) method of the view, I get blank pages. With the following more elaborate code, I get a partial printout, 11 out of what should be about 13 pages. let info = NSPrintInfo.shared info.topMargin = 72.0; info.bottomMargin = 72.0; info.leftMargin = 72.0; info.rightMargin = 72.0; info.isVerticallyCentered = false; info.isHorizontallyCentered = false; info.horizontalPagination = .fit; info.verticalPagination = .automatic; let printOp = webView!.printOperation( with: info ) printOp.canSpawnSeparateThread = true printOp.view?.frame = NSMakeRect( 0, 0, info.paperSize.width, info.paperSize.height ) printOp.runModal(for: webView.window!, delegate: self, didRun: nil, contextInfo: nil ) When I run the above under the debugger, I see console messages saying CGContextClipToRect: invalid context 0x0. Once the print dialog appears, if I touch (but not change) the selected printer, then the page count changes to the correct value.

"The Safari web extension packager enables you to package and distribute your Safari extensions using App Store Connect from any web browser, without requiring a Mac or access to Xcode." I upload the unzipped folder I'd test in Chrome://extensions to the Safari web extension packager in App store connect. I get error: Embedded binary's bundle identifier is not prefixed with the parent app's bundle identifier. The only solution i've seen to this error involves xcode/a mac, being without which doesn't help

We are seeing network errors in Outlook mail on iOS and MacOS safari browsers. As per current investigation, we notice these network error when the user tries to use outlook after leaving it open on Safari for a while. Observations: Issue present in both MacOS and iOS safari. Issue is not present in other webkit browsers like brave and edge on iOS. Issue is reproable on both mini and big owa on safari browser. Issue is not related to post requests being sent in different packets on safari browser. Requests are only blocked for outlook.office/outlook.live domains What does not fix this issue? Reloading the application Clearing cookie, local storage or session storage Unregistering service workers Redirecting to a different page and coming back to outlook domain Re authenticating the users What fixes this issue? Reconnecting to wifi or mobile network Reconnecting vpn Removing safari from background and reopening Flushing the dns in setting

Is this symbol, which Safari uses to the left of the address bar, in the public SF Symbols set? What's it called?

I have a content blocker that generally works correctly, but I need to block an element that has certain text in it. For example, <span id="theId">Some text</span> is easy enough to block because I can locate the id and block that, but what if there is no id, or the id is completely random? What if it's just <span>Some text</span>? How do I block that? Let's say this is my only content blocker rule: [ { "action": { "type": "css-display-none", "selector": ":has-text(/Some text/i)" }, "trigger": { "url-filter": ".*" } } ] No errors are seen when the rule is loaded, so it's syntactically correct, it just doesn't block the HTML. I gather this is because :has-text() works on attributes, not contents, so it works on alt, href, aria-label etc. but not on the contents of the element itself. How do I block Some text in my example above? Thanks!

Hi, We are facing a major issue with our application. We are using FolioReaderkit to read epub files. Currently, it's working on the iOS 18.1 device and simulator, but it's not working on the iOS 18.2 and later version devices. we are facing this error in Folioreaderkit

Hi, we are experiencing a strange issue with our Web App. Our web app runs entirely on the same domain , and we are making several AJAX requests to the same server. The Error occurs only on Iphones, the app works completely fine on androids and computers. Most of the requests work fine, but suddenly, one specific request always fails with the following error: XMLHttpRequest cannot load https://demo2.artios.cz/app37g/v105/php/endpoint.php due to access control checks What we have checked so far: ✅ CORS headers seem correct. Also we operate entirely on the same domain, client and server. ✅ The same request works fine in computer and android devices. ✅ The issue occurs only on iPhone (tested on Chrome and Safari). ✅ Some requests to the same endpoint pass, but suddenly, this specific request always fails. ✅ There is no OPTIONS preflight request logged in the network tab, but we use only simple requests. ✅ We are making a POST request with multipart/form-data. What is Your advice, or where I can find more info about this error? We do not think the CORS is the problem. We have tried to inspect with WebInspector but with no relevant answers. Thank You very much!

The crash is specific to iOS 26.2 WKScriptMessageHandler delegate func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) Name attribute is accessible but WKScriptMessage body attribute causes crash The object seems to be not accessible

Hello, my application experiences crashes related to JavaScriptCore in iOS 17 and 18. I would like to consult about potential causes, to determine whether it is a bug in JavaScriptCore or an issue with my code implementation. First, the crash stack always includes the call to JSC::MarkedBlock::aboutToMarkSlow(unsigned int). In the iOS 17 version, the crash occurs on this line, typically JSC::MarkedBlock::aboutToMarkSlow(unsigned int) + 88. In iOS 18 and later, the stack crashes atJSC::MarkedBlock::dumpInfoAndCrashForInvalidHandle(WTF::AbstractLocker&, JSC::HeapCell*). I checked the source code of JavaScriptCore for both iOS 17.6 and iOS 18.2 and observed modifications in the implementation of aboutToMarkSlow. My question is under what circumstances could this crash occur? crash.log I have attached a crash log encountered in iOS 18, hoping you can provide more effective information for problem diagnosis, especially since there are specific details worth noting near the crash registers. INVALID HANDLE: MarkedBlock = 0x141158000; heapCell = 0x14115bfa0; type = 0 INVALID HANDLE: found 24 0s at beginning of block INVALID HANDLE: block in another VM: 1, block in another VM: 1; other VM is 0x1324b6000 Moreover, in iOS 18.4, due to the implementation of dumpInfoAndCrashForInvalidHandleV2, the message has changed to: INVALID HANDLE 587: markedBlock=0x303518000; heapCell=0x303518fe0; cellFirst8Bytes=0; subspaceHash=0; contiguousZeros=0; totalzeros=0; blockVM=0x0; actualVM=0x0; isBlockVMValid=0; isBlockInSet=0; isBlockInDir=0; foundInBlockVM=0; INVALID HANDLE 606: markedBlock=0x303518000; heapCell=0x303518fe0; cellFirst8Bytes=0; subspaceHash=0; contiguousZeros=16384; totalZeros=16384; blockVM=0x0; actualVM=0x0; isBlockVMValid=0; isBlockInSet=0; isBlockInDir=0; foundInBlockVM=0; INVALID HANDLE 615: markedBlock=0x303518000; heapCell=0x303518fe0; cellFirst8Bytes=0; subspaceHash=0; contiguousZeros=16384; totalZeros=16384; blockVM=0x0; actualVM=0x0; isBlockVMValid=0; isBlockInSet=1; isBlockInDir=1; foundInBlockVM=0; (Further INVALID HANDLE messages follow the same format) I hope this provides you with more information.

I don't know why but all of a sudden when I build the extension it just doesn't load in Safari. The build executes fine but the extension doesn't load. Sometimes, through trying different combinations of clearing the build folder, building, archiving, ... it suddenly loads. And the next time I build again it doesn't load properly. So I can't do any work on it or test anything. I don't know why all of a sudden I am getting this behavior. It looks like engineers at Apple are constantly trying to overcomplicate a process that is at least ten times simpler in any other browser. This is ridiculous. Is this what our annual fee goes to? And they don't even provide any support for that. Several times I've tried to get some help here just to have to spend hours upon hours to figure it out by myself. I'm so tired of this.

I have an extension which was working fine on older Safari version, but it is getting killed after I upgraded the browser to Safari 18 and higher. From the system logs I could see, Safari is sending the KILL signal to my browser 2024-11-12 13:51:01.536167-0600 0x95b672 Default 0x0 1 0 launchd: [pid/45238/SafariExt [45463]:] signal service: caller = Safari[45238], value = 0x9 2024-11-12 13:51:01.536453-0600 0xfab Default 0x0 382 7 WindowServer: (SkyLight) [com.apple.SkyLight:default] [ ConnectionDebug ] Closing conn 0xf955b, PID 45463 in session 257 on console2024-11-12 13:51:01.536474-0600 0x95b674 Default 0x0 1 0 launchd: [gui/503 [100018]:] service inactive: com.apple.xpc.launchd.unmanaged.SafariExtension.45463 2024-11-12 13:51:01.536479-0600 0x95b674 Default 0x0 1 0 launchd: [gui/503 [100018]:] removing inactive unmanaged service: com.apple.xpc.launchd.unmanaged.SafariExtension.454632024-11-12 13:51:01.537354-0600 0x95b907 Default 0x0 354 0 launchservicesd: [com.apple.processmanager:front-35286506] QUITTING: pid=45463 asn=0x-0x176176 foreground=0 wasFront=0 2024-11-12 13:51:01.537375-0600 0x95b672 Default 0x0 1 0 launchd: [pid/45238/SafariExt [45463]:] exited due to SIGKILL | sent by launchd[1], ran for 342ms 2024-11-12 13:51:01.537380-0600 0x95b672 Default 0x0 1 0 launchd: [pid/45238/SafariExt [45463]:] service state: exited 2024-11-12 13:51:01.537384-0600 0x95b672 Default 0x0 1 0 launchd: [pid/45238/SafariExt [45463]:] internal event: EXITED, code = 0 2024-11-12 13:51:01.537385-0600 0x95b672 Default 0x0 1 0 launchd: [pid/45238/SafariExt [45463]:] job state = exited Just before this, I see a macOS error 2024-11-12 13:51:06.789342-0600 0x95b74f Default 0x0 45238 0 Safari: (Security) [com.apple.securityd:security_exception] MacOS error: -67054 This occurs only in my customer machines but not in my test machines. I have verified the code signing, certificate validity & entitlements are fine.

I’m encountering an issue with CSS not displaying when using WKURLSchemeHandler to load local HTML files. When I package the app using Xcode 15.3 or above, the CSS styles do not display on iOS 17 or higher. However, on iOS 16.7.1, the CSS displays correctly. • If I use Xcode 15.2 to package the app, the CSS loads and displays correctly on all iOS versions. I am using WKURLSchemeHandler to intercept and load the local HTML files. Is there any known issue or workaround for this? You can now post this in the “Safari & Web” section of the Apple Developer forums for further assistance! // // CustomURLSchemeHandler.m // HTMLTest // // Created by lvxue on 2024/9/23. // // CustomURLSchemeHandler.m #import "CustomURLSchemeHandler.h" @implementation CustomURLSchemeHandler - (void)webView:(WKWebView *)webView startURLSchemeTask:(id<WKURLSchemeTask>)urlSchemeTask { NSURL *url = urlSchemeTask.request.URL; //NSString *filePath; NSString *filePath = [[NSBundle mainBundle] pathForResource:@"index" ofType:@"html" inDirectory:@"LoaclHtml.bundle/A4"]; if ([url.lastPathComponent hasSuffix:@".css"]) { filePath = [[NSBundle mainBundle] pathForResource:@"style" ofType:@"css" inDirectory:@"LoaclHtml.bundle/A4/css"]; } else if ([url.lastPathComponent hasSuffix:@".js"]) { filePath = [[NSBundle mainBundle] pathForResource:@"yourJSFileName" ofType:@"js" inDirectory:@"LoaclHtml.bundle/A4/js"]; } NSData *htmlData = [NSData dataWithContentsOfFile:filePath]; NSString *mimeType = [self mimeTypeForPath:filePath]; NSURLResponse *response = [[NSURLResponse alloc] initWithURL:url MIMEType:mimeType expectedContentLength:htmlData.length textEncodingName:@"utf-8"]; [urlSchemeTask didReceiveResponse:response]; [urlSchemeTask didReceiveData:htmlData]; [urlSchemeTask didFinish]; } - (void)webView:(WKWebView *)webView stopURLSchemeTask:(id<WKURLSchemeTask>)urlSchemeTask { } - (NSString *)mimeTypeForPath:(NSString *)path { NSString *fileExtension = [path pathExtension]; if ([fileExtension isEqualToString:@"html"]) { return @"text/html"; } else if ([fileExtension isEqualToString:@"css"]) { return @"text/css"; } else if ([fileExtension isEqualToString:@"js"]) { return @"application/javascript"; } else if ([fileExtension isEqualToString:@"png"]) { return @"image/png"; } else if ([fileExtension isEqualToString:@"jpg"] || [fileExtension isEqualToString:@"jpeg"]) { return @"image/jpeg"; } else if ([fileExtension isEqualToString:@"gif"]) { return @"image/gif"; } return @"application/octet-stream"; } @end code-block

It seems fetch() does not include credentials (cookie) even when credentials: include is used and Safari extension has host_permissions for that domain when using from a non-default Safari profile. It includes credentials (cookie) when using from the default profile (which has the default name Personal). Is there anyone who has this problem? I try to request in popup.js like this: const response = await fetch( url, { method: 'GET', mode: 'cors', credentials: 'include', referrerPolicy: 'no-referrer', } ); and it does not include the credentials (cookie) from host_permissions. I already posted https://developer.apple.com/forums/thread/764279, and opened feedback assistant (FB15307169). But it is still not fixed yet. (macOS 15.4 beta 3) I hope this is fixed soon.

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)

We’ve noticed that the ApplePaySession.applePayCapabilities() check has stopped working correctly in Safari over the past couple of days. Behavior observed: 1.) In Safari Private Window, paymentCredentialStatus behaves as expected and case 1 is triggered. 2.) In a normal Safari window, it always triggers case 3 (paymentCredentialsUnavailable), even when the user has active cards provisioned in Wallet. We tested across multiple devices, and the behavior is consistent. if (window.ApplePaySession) { var merchantIdentifier = 'YOUR MERCHANT IDENTIFIER'; var promise = ApplePaySession.applePayCapabilities(merchantIdentifier); promise.then(function(capabilities) { switch (capabilities.paymentCredentialStatus) { case "paymentCredentialsAvailable": // Show Apple Pay button as primary option case "paymentCredentialStatusUnknown": // Offer Apple Pay case "paymentCredentialsUnavailable": // Consider showing Apple Pay button case "applePayUnsupported": // Don’t show Apple Pay button } }) } This used to work fine until a few days ago, but now the capability check in non-private Safari windows always indicates unavailable, even with valid active cards. Has anyone else faced this issue recently? Could this be a Safari regression or a change on Apple’s side? Thanks in advance!