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App’s navigation bar items change background color unexpectedly
iPadOS 26, dark mode Open Safari Search for anything or open a website that has white background Kill Safari Open Safari again I still can reproduce it with Safari on iPadOS 26.0.1 This issue also happens to my app when opening a HTML/JS on WKWebView with white background while using dark mode. I did send a feedback ticket when using iPadOS 26 beta but havent seen any reply. This is my first time sending a feedback so I dont know if Apple would reply or not.
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Oct ’25
iOS 26 WKWebView PDF Background Color Changed to Gray
Hello We've encountered an issue with WKWebView in the latest iOS 26 beta. When loading a PDF URL, the background of the PDF viewer now displays as a dark gray instead of the expected white. Device: iOS 26 Simulator/Device Component: WKWebView Issue: The background color of the loaded PDF is gray. Expected Behavior: The background should be white, as it has been in all previous iOS versions. Link for Testing: https://help.apple.com/pdf/security/en_US/apple-platform-security-guide.pdf We confirmed that the same PDF and code render with a white background on iOS 26 and earlier. Questions: Is this an intentional change in iOS 26's WKWebView? If so, is there a new property or configuration setting available to control the background color of the PDF viewer within WKWebView? We would like to have the ability to set it back to white. Any insights, workarounds, or information on this matter would be greatly appreciated. Thank you.
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308
Nov ’25
Referer not being sent by WKWebView when using a custom scheme
YouTube now requires a Referer to be sent to be able to embed Youtube videos, otherwise the videos won't work. But WKWebView doesn't send a Referer when using a custom scheme, so Youtube videos stopped working in that case. This affects Ionic apps, both using Cordova or Capacitor. There's an open issue for Cordova and another one for Capacitor. In these apps, the app is served using a custom scheme like capacitor://localhost or ionic://localhost. I tried modifying the Ionic WebView source code to force adding a referrer to the URL loaded using WKWebView's loadRequest: [request addValue:@"https://my.test.app" forHTTPHeaderField:@"Referer"]; [_engineWebView loadRequest:request] But the Referer is still not sent in the Requests, I guess because the app is using a custom scheme (e.g. capacitor://localhost). However, if I modify this code to force loading an "online URL" (using https) instead of capacitor://localhost, then the my.test.app Referer is sent to the requests. Is there any way to make WKWebView send a Referer when using a custom scheme?
Topic: Safari & Web SubTopic: General Tags:
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153
Nov ’25
WebGPU supporting in Safari on macOS
Hi, now we could try WebGPU by manually enabling it in feature flags in no matter Safari or Safari technology preview on macOS. But, do we know when this WebGPU feature would be enabled by default or any plan to enable it by default in Safari? Thanks!
Topic: Safari & Web SubTopic: General
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Feb ’25
New IOS Safari CSS Issue with DVH & VH
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?
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Oct ’25
declarativeNetRequest redirect action causing page reload/error in Safari 26.0
After updating to Safari 26.0 (on macOS Sequoia or Tahoe), the Declarative Net Request (DNR) API rule with "type": "redirect" no longer works as expected. When the rule is applied, the browser initially shows a banner at the top of the page: "This webpage was reloaded because a problem occurred." After the reload, the page fails to load and displays an error page with the message: "A problem repeatedly occurred with https://extensionworkshop.com/?test=true " This behavior is new in Safari 26.0. The same rule was working correctly in earlier Safari versions (17.x / 18.x).
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Oct ’25
JavaScriptCore crashed in iOS 17 and iOS 18
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.
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707
Mar ’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.
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Oct ’25
Issues Observed with App Clip Behavior and URL Handling
Hi Apple Team, We’ve noticed a couple of issues with launching default App Clip in safari and would appreciate your guidance. App Clip Popup Timing: When launching the App Clip using default URL, we sometimes see the small App Clip popup appear before the App Clip banner is displayed. Ideally, the banner should appear first. Cached URL Handling: In certain cases, the App Clip appears to be using a cached URL instead of the most recent one. For example, when we invoke two different App Clip URLs with unique parameters, the App Clip sometimes launches using the previous URL’s data instead of the new one. This behavior is inconsistent and makes it difficult to ensure users are directed to the correct experience each time. Could you please help us understand whether this is expected behavior or if there are any known issues or recommended solutions? Thank you for your time and support. Example
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190
Oct ’25
Safari App crashes when running with Safari extension intermittently
I have observed Safari App starts crashing when running with my safari extension. Our Safari extension polls the host app every 60s. The extension receives and completes requests in func beginRequest(with context: NSExtensionContext) (we always call context.completeRequest(...)). The crash is intermittent: beginRequest itself does not throw. Looking for guidance about likely causes. I am attaching the snippet from crash report. Crashed Thread: 0 Dispatch queue: com.apple.main-thread Exception Type: EXC_CRASH (SIGKILL) Exception Codes: 0x0000000000000000, 0x0000000000000000 Termination Reason: Namespace RUNNINGBOARD, Code 3490524077 Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 libsystem_kernel.dylib 0x1856f5c34 mach_msg2_trap + 8 1 libsystem_kernel.dylib 0x1857083a0 mach_msg2_internal + 76 2 libsystem_kernel.dylib 0x1856fe764 mach_msg_overwrite + 484 3 libsystem_kernel.dylib 0x1856f5fa8 mach_msg + 24 4 CoreFoundation 0x185822cbc __CFRunLoopServiceMachPort + 160 5 CoreFoundation 0x1858215d8 __CFRunLoopRun + 1208 6 CoreFoundation 0x185820a98 CFRunLoopRunSpecific + 572 7 HIToolbox 0x1912c327c RunCurrentEventLoopInMode + 324 8 HIToolbox 0x1912c64e8 ReceiveNextEventCommon + 676 9 HIToolbox 0x191451484 _BlockUntilNextEventMatchingListInModeWithFilter + 76 10 AppKit 0x189745a34 _DPSNextEvent + 684 11 AppKit 0x18a0e4940 -[NSApplication(NSEventRouting) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 688 12 Safari 0x1b801cce4 -[BrowserApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 228 13 AppKit 0x189738be4 -[NSApplication run] + 480 14 AppKit 0x18970f2dc NSApplicationMain + 880 15 Safari 0x1b83dd0b0 SafariMain + 468 16 dyld 0x185396b98 start + 6076
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Sep ’25
Missing Cookies in Set-Cookie Header in webRequest.onHeadersReceived callback in Safari Web Extension
We’re seeing an issue in our Safari Web Extension where not all cookies from the Set-Cookie response header are accessible. We are using macOS 15.4 and Safari 18.4. In the webRequest.onHeadersReceived callback, the Set-Cookie header returned by Safari only includes some of the cookies set by the server. If multiple Set-Cookie headers are present, we seem to receive only a partial list, some cookies are missing entirely. In Chrome and Firefox, the same callback provides all cookies set by the server without issue. We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.
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193
Apr ’25
No longe rable to obtain network name
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
Topic: Safari & Web SubTopic: General
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Oct ’25
Web view delayed layout during window resize
The app I work on uses WKWebView to render customer data. In iPadOS 26, we observe that there is a delay when resizing the window (and thus the web view) before the content is re-rendered. The same behavior is visible in Safari. For demonstration purposes, consider this test page: https://phet-dev.colorado.edu/html/build-an-atom/0.0.0-3/simple-text-only-test-page.html Initially, the window is small: Then when the window is expanded, the content scales up temporarily: It eventually re-renders to the correct size, but then if you make the window small again, you get (temporarily): Is there anyway around this behavior? We would love to have the content reflow interactively.
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349
Sep ’25
Simulator 18.4 Webview CORS issues
I have a very specific issue that happens only on iOS Simulator version 18.4. It does NOT happen when I run my app on a real iOS 18.4 device through Testflight. My app displays a WebView (courtesy of Capacitor, url scheme capacitor://). Inside that Webview I'm using Firebase JS API (11.2.0) and calling signInWithEmailAndPassword, which works well in all other contexts, i.e. browser, Android webview, iOS webview in all other Simulator versions, and on real devices. Only when running in Simulator 18.4, I get a failed network request: cannot parse response Fetch API cannot load https://identitytoolkit.googleapis.com/v1/accounts:signInWithPassword?... due to access control checks. Failed to load resource: cannot parse reponse error: FirebaseError: (auth/network-request-failed) Everything is working correctly for both: Capacitor app webview installed on a real 18.4 device with Testflight Safari (non-webview) in the 18.4 Simulator The issue is severe for us, because we are unable to develop our app and test it in the simulator on 18.4 Simulator before pushing it through Testflight internal release. Request headers on the failed request (no response status or headers available). Request Accept: / Content-Type: application/json Origin: capacitor://localhost Sec-Fetch-Dest: empty Sec-Fetch-Mode: cors Sec-Fetch-Site: cross-site User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_4 like Mac OS X) - AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 X-Client-Version: Mobile/JsCore/11.2.0/FirebaseCore-web X-Firebase-Client: (...)
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Apr ’25
I want to specify the background color for the header notch and footer indicator area when opening the browser in Safari on iOS 26.
When I open the browser in Safari on iOS 26, I want to specify the background color for the header notch (where the time, battery, etc. are displayed) and the footer indicator area. Specifying the theme color in HTML as shown below did not change anything. <meta name="theme-color" content="#ff0000"> <meta name="theme-color" media="(prefers-color-scheme: light)" content="#ff0000"> <meta name="theme-color" media="(prefers-color-scheme: dark)" content="#ff0000"> The HTML below specifies the background color as green, but is it necessary to specify the background color directly in the body like this? Or is there some kind of metadata, like theme color? <!doctype html> <html lang="ja"> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width,initial-scale=1" /> <meta name="theme-color" content="#ff0000"> <meta name="theme-color" media="(prefers-color-scheme: light)" content="#ff0000"> <meta name="theme-color" media="(prefers-color-scheme: dark)" content="#ff0000"> <title>サンプル</title> </head> <body style="background:#00ff00"> <main> <p>テキスト</p> </main> <div id="overlay" role="dialog" aria-modal="true" data-test-id="health-warning-modal" style=" color:#000000; position:fixed; inset:0; z-index:30000; background:#2563eb; display:grid; /* 初期表示:表示中 */ align-items:center; justify-content:center; overflow-y:auto; " > <div style=" padding:60px 16px; display:flex; flex-direction:column; gap:20px; width:100%; box-sizing:border-box; " > <p style=" font-weight:700; text-align:center; margin-top:20px; font-size:28px; line-height:1.4; " > オーバーレイ </p> </div> </div> </body> </html>
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Sep ’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:
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Mar ’25
Safari Extension Stops on iOS 17.5.1 - 18
We are encountering an issue where the Safari extension we are developing stops working while in use on relatively new iOS versions (confirmed on 17.5.1, 17.6.1, and 18). Upon checking the Safari console, the content script is displayed in the extension script, so the background script or Service Worker must be stopping. The time until it stops is about 1 minute on 17.5.1 and about one day on 17.6.1 or 18. When it stops, we would like to find a way to restart the Service Worker from the extension side, but we have not found a method to do so yet. To restart the extension, the user needs to turn off the corresponding extension in the iPhone settings and then turn it back on. As mentioned in the following thread, it is written that the above bug was fixed in 17.6, but we recognize that it has not been fixed. https://forums.developer.apple.com/forums/thread/758346 On 17.5.1, adding the following process to the background script prevents it from stopping for about the same time as on 17.6 and above. // Will be passed into runtime.onConnect for processes that are listening for the connection event const INTERNAL_STAYALIVE_PORT = "port.connect"; // Try wake up every 9S const INTERVAL_WAKE_UP = 9000; // Alive port var alivePort = null; // Call the function at SW(service worker) start StayAlive(); async function StayAlive() { var wakeup = setInterval(() => { if (alivePort == null) { alivePort = browser.runtime.connect({ name: INTERNAL_STAYALIVE_PORT }); alivePort.onDisconnect.addListener((p) => { alivePort = null; }); } if (alivePort) { alivePort.postMessage({ content: "ping" }); } }, INTERVAL_WAKE_UP); } Additionally, we considered methods to revive the Service Worker when it stops, which are listed below. None of the methods listed below resolved the issue. ① Implemented a process to create a connection again if the return value of sendMessage is null. The determination of whether the Service Worker has stopped is made by sending a message from the content script to the background script and checking whether the message return value is null as follows. sendMessageToBackground.js let infoFromBackground = await browser.runtime.sendMessage(sendParam); if (!infoFromBackground) { // If infoFromBackground is null, Service Worker should have stopped. browser.runtime.connect({name: 'reconnect'}); // ← reconnection process // Sending message again infoFromBackground = await browser.runtime.sendMessage(sendParam); } return infoFromBackground.message; Background script browser.runtime.onConnect.addListener((port) => { if (port.name !== 'reconnect') return; port.onMessage.addListener(async (request, sender, sendResponse) => { sendResponse({ response: "response form background", message: "reconnect.", }); }); ② Verified whether the service worker could be restarted by regenerating Background.js and content.js. sendMessageToBackground.js export async function sendMessageToBackground(sendParam) { let infoFromBackground = await browser.runtime.sendMessage(sendParam); if (!infoFromBackground) { executeContentScript(); // ← executeScript infoFromBackground = await browser.runtime.sendMessage(sendParam); } return infoFromBackground.message; } async function executeContentScript() { browser.webNavigation.onDOMContentLoaded.addListener((details) => { browser.scripting.executeScript({ target: { tabId: details.tabId }, files: ["./content.js"] }); }); } However, browser.webNavigation.onDOMContentLoaded.addListener was not executed due to the following error. @webkit-masked-url://hidden/:2:58295 @webkit-masked-url://hidden/:2:58539 @webkit-masked-url://hidden/:2:58539 ③ Verify that ServiceWorker restarts by updating ContentScripts async function updateContentScripts() { try { const scripts = await browser.scripting.getRegisteredContentScripts(); const scriptIds = scripts.map(script => script.id); await browser.scripting.updateContentScripts(scriptIds);//update content } catch (e) { await errorLogger(e.stack); } } However, scripting.getRegisteredContentScripts was not executed due to the same error as in 2. @webkit-masked-url://hidden/:2:58359 @webkit-masked-url://hidden/:2:58456 @webkit-masked-url://hidden/:2:58456 @webkit-masked-url://hidden/:2:58549 @webkit-masked-url://hidden/:2:58549 These are the methods we have considered. If anyone knows a solution, please let us know.
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Aug ’25