It seems that in iOS 18.5+ built with Xcode 16.4+, there has been a breaking change since 18.4 with 16.3 within WebKit and how the navigationAction.sourceFrame property is initialized when implementing the decidePolicy delegate method. The flow goes: Implement a WKNavigationActionDelegate with decidePolicy Call WKWebView.loadHTMLString("some-string", baseURL: nil) Upon loading the HTML content, read the value of navigationAction.sourceFrame within the decidePolicy method of the WKNavigationActionDelegate On iOS 18.4 (and below) with Xcode 16.3 (and below); navigationAction.sourceFrame is <uninitialized> On iOS 18.5+ with Xcode 16.4+: navigationAction.sourceFrame is already initialized and is equal to navigationAction.targetFrame It appears that this change was made between minor versions of Xcode and is unexpected behavior of a minor version. Not only was this not called out in the release notes for Xcode 16.4 and iOS 18.5, but it's technically also a breaking change to the WebKit API. Can we get insight on why this change was made and what Apple's policy is on breaking changes between minor versions of Xcode/iOS?

The crash is specific to iOS 26.2 prior versions working fine. 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(not in memory) self.webkit.configuration.userContentController.add(self, name: "sampleHandler") self.webkit.load(request) func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) { print(message.name) // works print(message.body) // crashes }

Since iPadOS 18.x WKWebView seems to have a bug within its Fullscreen API (which can be enabled via WKPreferences.isElementFullscreenEnabled). This bug has the effect that websites trying to make an element (for example a video player) fullscreen fail to do so. This does not always happen, most of the time the fullscreen mode does work fine, but sometimes (far too often to be ignored) it does not. If an instance of WKWebView shows this issue, it can not be "fixed" by reloading the page or loading other pages, this issue exists in this instance forever. My App is a web browser App so I can create and remove WKWebView instance easily (by opening or closing Tabs). And there are times where I never see this bug, and times where ever other tab shows this bug. It's totally unreliable. The App does not show any issues at all when running under iPadOS 17 or older. The issue is only present under iPadOS 18.x. After some testing I've found out that when the bug has affected an instance of WKWebView, the JavaScript call element.requestFullscreen() will work if the element is a video element, but does no longer work if it is another element (like a DIV). If an instance of WKWebView is not affected by this bug, element.requestFullscreen() will work for all HTML elements. Does anyone has experienced this bug as well? And maybe found a workaround? Or maybe found a pattern which helps to find out what exactly is triggering this bug?

Hi, I'm developing an extension and I need to debug console logs that are logged in the Service Worker. The worker is configured in the manifest and is generally working as expected: However, when I open the browser, go to any site, and open Develop -> Service Workers or Develop -> Web Extension Background Content it is not visible there, so I can't really access the logs: But then I noticed that if I go out of focus from the browser for some time (and probably let the SW die), it becomes visible and I can open it without an issue: So, a couple of questions: Why isn't it instantly accessible? The extension Service Worker dev tools should be accessible regardless of what is happening to the tab or the browser, even if the SW terminates. Why does it eventually appear under Web Extension Background Content instead of the Service Workers when it is in fact an SW?

Dear Apple Developer Support, We are currently developing a system that requires the ability to edit Japanese vertical text within the Safari browser on iPhone. During our investigation, we encountered an issue that matches the following WebKit bug: 283620 – Caret Positioning Issues in Vertical Writing Mode We understand that this issue is being addressed in the following pull request: https://github.com/WebKit/WebKit/pull/39939 However, it appears that a complete fix has not yet been implemented. Given this situation, we would like to confirm the following: Is there any known workaround for this issue in iOS 17.5 or iOS 18.5 (the latest versions as of now)? If a workaround exists, could you please provide details? If not, could you share the expected timeline for a full resolution of this issue? Although this appears to be an open-source WebKit issue, we are reaching out to Apple because WebKit is tightly integrated with iOS and Safari, and ultimately delivered as part of the iPhone experience. Thank you very much for your support. Best regards, Takao Kurabayashi

Hi! I configure proxy for webview like DispatchQueue.main.async { self.webView.configuration.websiteDataStore.proxyConfigurations = [proxyConfiguration] } It is fine in iosiOS 17 however, it crashes in iOS 18.3. And the problem seems to be related to the left side of the equation. I tried to call print(self.webView.configuration.websiteDataStore.proxyConfigurations.count) in async block and got the same bad access error. But if stop at that line of code and call po self.webView.configuration.websiteDataStore.proxyConfigurations in debugger it returns 0 elements. Did anyone have the same problem? What may cause the exception?

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 !

I'm not loving the huge Favorites icons in Safari on MacOS 26, is there a way to reduce the size of them so that we can see more favorites on the list without scrolling down?

DNR rules redirecting to an extension path lead to an error page: “Safari can’t open the page. The error is: “The operation couldn’t be completed. (NSURLErrorDomain error -1008.)” (NSURLErrorDomain:-1,008).” Here is a demo extension that replicates the bug: https://github.com/lenacohen/Safari-Test-Extensions/tree/main/dnr-extension-path-redirect This is an example of a redirect rule that leads to an error page instead of the extension path page: chrome.declarativeNetRequest.updateDynamicRules({addRules: [ { id: 2, priority: 1, action: { type: "redirect", redirect: { extensionPath: "/web_accessible_resources/test_redirect.html" } }, condition: { urlFilter: "||washingtonpost.com^", resourceTypes: [ "main_frame" ] } } ]}); The extension path is included in web_accessible_resources in the extension manifest: "web_accessible_resources": [{ "resources": [ "web_accessible_resources/test_redirect.html" ], I also submitted a bug report on Apple's Feedback Assistant: FB16607632

Our app connects to the headend to get a IDP login URL for each connection session, for example: “https://myvpn.ocwa.com/+CSCOE+/saml/sp/login?ctx=3627097090&amp;acsamlcap=v2” and then open embedded webview to load the page. (Note: the value of ctx is session token which changes every time). Quite often the webview shows blank white screen. After user cancel the connection and re-connect, the 2nd time webview loads the content successfully. The working case logs shows: didReceiveAuthenticationChallenge is called decidePolicyForNavigationAction is called twice didReceiveAuthenticationChallenge is called decidePolicyForNavigationResponse is called didReceiveAuthenticationChallenge is called But the failure case shows: Filed to terminate process: Error Domain=com.apple.extensionKit.errorDomain Code=18 "(null)" UserInfo={NSUnderlyingError=0x11461c240 {Error Domain=RBSRequestErrorDomain Code=3 "No such process found" UserInfo={NSLocalizedFailureReason=No such process found}}} didReceiveAuthenticationChallenge is called decidePolicyForNavigationAction is called decidePolicyForNavigationResponse is called If we stop calling evaluateJavaScript code to get userAgent, the blank page happens less frequently. Below is the code we put in makeUIView(): func makeUIView(context: Context) -&gt; WKWebView { if let url = URL(string: self.myUrl) { let request = URLRequest(url: url) webview.evaluateJavaScript("navigator.userAgent") { result, error in if let error = error { NSLog("evaluateJavaScript Error: \(error)") } else { let agent = result as! String + " " + self.myUserAgent webview.customUserAgent = agent webview.load(request) } } } return self.webview } Found some posts saying call evaluateJavaScript only after WKWebView has finished loading its content. However, it will block us to send the userAgent info via HTTP request. And I don’t think it is the root cause since the problem still occurs with less frequency. There is no problem to load same web page on Windows desktop and Android devices. The problem only occurs on iOS and macOS which both use WKWebview APIs. Is there a bug in WKWebview? Thanks, Ying

I'm working on a Safari web extension that uses the nativeMessaging facility to communication with native code. When I want to notify the javascript extension from the embedding application, I use SFSafariApplication::dispatchMessage. As per the documentation, this call ... ensures that Safari is launched and that your extension is running before delivering the message. Everything works fine when the background script is running. However, after the background script gets unloaded at some point in time (non persistent background page, default behavior for a manifest V3 extension), the background script is not reloaded by the message from the native app (background script still appears unloaded in the developer menu of Safari, double-checked using a counter stored in browser.storage.local incremented on message reception). In this case, the completion handler of the application gets no error (error == nil) as if the message was correctly delivered. I was able to reproduce this behavior with the sample app delivered for WWDC20 (after upgrading the manifest from v2 to v3 to make it non-persistent). Is it supposed to work ? What I'm doing wrong ?

Based on the "Build immersive web experiences with WebXR"-Video for visionOS there is no way to disable the consent prompts for entering an immersive experience or consent hand-tracking. For the microphone it's possible to "greenlight" specific websites for mic input, which works great. I'd welcome it, if it were possible to add specific websites in the settings, in which those consent dialogs aren't shown each time. In my opinion, the user interaction through a button that launches the experience would be sufficient to not disorient.

Our current iOS application utilizes WKWebView to display a web application. We've observed intermittent deletion of non-expired 1st-party persistent cookies within this web application, leading to session drops. Here are our environment details and specific questions: Environment: App Build: Built with Xcode 16.2. WebView Class: WKWebView. Cookie Type: 1st-Party Persistent Cookie (Explicit expiration set, not a session cookie). Domain Configuration: The content server and the cookie-issuing server are the same (same IP address, same eTLD+1). The Cookie is set via the Set-Cookie HTTP Header on the server side. Questions: Automatic Deletion Policy: Are there any scenarios (e.g., related to iOS system behavior, Safari policies, or Intelligent Tracking Prevention (ITP)) where iOS or Safari might automatically delete non-expired 1st-party persistent cookies used by WKWebView? Deletion Conditions: If the answer to Q1 is Yes, under what specific conditions (e.g., memory pressure, inactivity, storage limits, specific ITP criteria) does this cookie deletion occur, and does the behavior differ significantly across various iOS versions? OS Update Impact: Are there any known specifications or documented cases where an iOS version update itself triggers the mass deletion of existing cookies stored in the WKWebsiteDataStore? Mitigation Strategy: If this automatic deletion is a known behavior, what mitigation strategies are officially recommended to ensure the persistence of essential 1st-party authentication cookies (e.g., manual synchronization with WKHTTPCookieStore or Keychain/UserDefaults)? Official Documentation: If the answer to Q1 is Yes, please provide URLs to any official Apple documentation or technical notes that detail the specifications or behavior of 1st-party persistent cookie deletion within WKWebView.

PLATFORM AND VERSION iOS Development environment: Xcode 16.2, macOS 15.3.2 Run-time configuration: iOS 15-18 This happens in iOS, and leads to to the hybrid home page showing users as wrongly unauthenticated, since the at cookie is missing. For context, we have a JWT token that is stored in the Keychain, and on app launch, before any WKWebViews are created, we synchronize this to the WKWebsiteDataStore as an at cookie. We have analytics instrumentation on our websitef to show that WKWebView randomly refuses to send out any cookies. – The following is a snippet from an explanation to the WebKit Slack: We are having an issue on iOS, in which WKWebView loads pages (and even subsequent reloads) without any cookies, even though we have stored cookies in WKWebsiteDataStore.default() before hand right after application launch and becoming a key window. We reference this object, store it as a singleton, (as well as a process pool), and then all webview configurations are initialized with the same data store, the same process pool, every call on the main thread. From reading the source code, it seems that if the internal IPC logic fails, the APIs for deleting and setting data records and cookies fail without any feedback in completion handlers. This bug often happens when returning from the background on iOS after a few hours. Sometimes it happens on cold launches of the app. We have mitigated a similar issue (no cookies being sent) by implementing webViewWebContentProcessDidTerminate and reloading the webview ourselves, we found that whatever webview does to reload if that method is not implemented leads to cookies not being used. There have been multiple reports of WKWebView losing cookies in recent iOS versions, and we have tried to implement all of the workarounds listed. Setting a maximumAge to the cookies we store, and doing a _ = await websiteDataStore.dataRecords(ofTypes: Set([WKWebsiteDataTypeCookies])) before accessing or modifying websiteDataStore.httpCookieStore Question: is it safe to work with WKWebsiteDataStore before a WKWebView is added as a view, if so are there any timing considerations? Are there any logs that we can take a look at, this issue is very hard to reproduce, about 2% of our users face it at scale? Is there anything that could be happening within our process (runloop issues, timing) that could be causing this issue? See multiple reports from other companies that have faced the issue: "Now the Thermonuclear Problem with WKWebViewDataStorage" https://medium.com/axel-springer-tech/synchronization-of-native-and-webview-sessions-with-ios-9fe2199b44c9 STEPS TO REPRODUCE They don't exist, because the issue only happens at scale. We just know that no cookies are sent for a small percentage of requests. We believe this to be an issue in which Webkit fails to communicate internally with whatever IPC mechanisms it has. We have not been able to reproduce this issue consistently. The best we can give is that it happens after a few hours that the app is in the background. This happens regardless of whether the WKWebsiteDataStore is persistent or not, but seems to be much worse when it is persistent. Thus we have disabled persistnet data stores and relied on nonPersistent. The issue is bad enough that we are trying to move away from relying on cookies for iOS and just use request headers which we can only set on the top level request of WKWebView. DTS Case-ID: 13154329

Hi, I have an app that uses WKWebView and it's crashing on iOS 26 Simulator in places I've never had problems before. In this case it's crashing when calling WKWebView.callAsyncJavaScript, but in my other project WKWebView is crashing with some sort of EXC_BAD_ACCESS other than callAsyncJavaScript. Am I missing something? Thanks,

We are experiencing a compatibility issue with our hybrid app related to the recent update in iPadOS 18.4, specifically concerning HTTPS connections. What are the key changes introduced in iPadOS 18.4 regarding HTTPS connections? Our app previously managed to bypass the DigitalSignature key usage missing error in the self-signed server certificate within the didReceiveAuthenticationChallenge method, as documented here: https://developer.apple.com/documentation/webkit/wknavigationdelegate/webview(_:didreceive:completionhandler:) . However, since the update to iPadOS 18.4, this method is no longer being called, resulting in direct failure of HTTPS connections. We are using cordova-ios 7.1. Thanks in advance for your help.

Ever since the iOS and iPadOS 26.2 beta I can’t open Safari at all. Safari tries to open but crashes and goes back to my home screen. I’ve restored my devices and restarted everything and the same issue occurs. I didn’t have this problem on the beta 26.1 but this whole thing started on 26.2.

Hello everyone, We are encountering a specific issue on iOS devices (iPhone 15 Pro in our case) when using Safari and Chrome. The problem occurs when switching an element's overflow-x property from hidden to scroll while the user keeps their finger on the screen. Problem Description: The overflow-x property change does not trigger a reflow or render update immediately. This behavior causes the element to remain visually stuck in the previous hidden state until the user lifts their finger and interacts again. Context: The element is animated. The issue happens consistently when the user's finger remains on the screen during the property transition. What We’ve Tried: Explicitly forcing styles using element.style in JavaScript. Triggering element.offsetWidth or getBoundingClientRect() to force reflow. Applying manual transform changes in combination with overflow updates. Unfortunately, none of these approaches resolve the issue in real-time while the user’s finger is on the screen. Questions: Is there a recommended way to force a reflow or repaint in Safari/Chrome on iOS under these conditions? Are there known limitations with overflow-x transitions and user touch events on iOS? Are there any workarounds or best practices to handle such cases? Thank you in advance for any insights!

WKWebView has a new property "isBlockedByScreenTime" since iOS 26. But I do not yet understand when exactly this property could be used. When I setup content-based restrictions in the ScreenTime settings then WKWebView reports an error 105 via "webView:didFailProvisionalNavigation:" delegate. The isBlockedByScreenTime property still returns false in this case. If ScreenTime has a time-based limit, the App would not run at all. Under which circumstances would the property "isBlockedByScreenTime" return the value true? When exactly and for what can this property be actually used? The "problem" is that I want to find if a web page is blocked and can not be loaded, why this is the case. By simply trial and error I found out that WKWebView returns error codes 104 and 105 for blocked web sites because of content filters and Screen Time restrictions, however these error codes are not documented at all (at least I've not found any documentation or documentation for these error codes and also some other codes like 100, 102, 204 etc), so I'm not really sure if I handle all cases correctly. I hoped that isBlockedByScreenTime would at least tell me one reason for blocked pages. If there are documents which explain these error codes (100 and above), where I can find these?

Hi there I've been having trouble finding any details around how safari is supposed to behave when a FairPlay license expires. My assumption was that the video segments would stop getting decrypted and playback would stop, however I just see that the playback continues like nothing has happened. I've setup the "fps_safari_has_key_renewal.html" sample code from the Fairplay SDK and got encrypted playback working. The renewal method also appears to work. However, if I don't issue a renew call, or if I wait several minutes after the renew has succeeded the video never stops (my license is set with a 1 minute expiry so I can test this quickly). I've also observed that the MediaKeySession expiration property is always set to NaN even though my license has an expiry. I've tried with both Lease and Rental expiries set in the license (separately AND at the same time in separate tests). I'm using EZDRM as my drm provider. Just looking for some feedback on if this is supposed to work this way in safari or if license expiry isn't supported in safari. Thanks!