Hello, I am developing Safari Content Blocker extension and discovered that it frequently fails to load with large amount of rules. Currently I have over 45k and most of the time when I reload the extension on iOS 18 (iPhone 12) it ends with error: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.apple.SafariServices.ContentBlockerLoader" UserInfo={NSDebugDescription=connection to service named com.apple.SafariServices.ContentBlockerLoader} #0 And the simpler message is just: Couldn’t communicate with a helper application. From what I managed to find (for example here - https://developer.apple.com/forums/thread/756931) the limit for blocking rules should be 150k items. It was previously 50k but got increased years ago. Is there anything special I need to do to get the extension to work reliably with say 100k items? I am usng the JSON format from the docs: { "trigger": { ... }, "action": { ... } }, { "trigger": { ... }, "action": { ... } } ] My trigger is url-filter and the action is type: block I was thinking about providing multiple JSON files in attachments property of NSExtensionItem but apparently that is not supported. Thanks for help!

I have a Safari App Extension which allows users to switch between last open tabs with a shortcut option+tab in the same way it's possible to switch between last open apps with command+tab. Here is how i do it: I inject a content script on all websites which has the only thing – key listener for option+tab presses. When a user presses option+tab, that keyboard listener detects it and sends a message to the Safari Handler. Then Safari Handler sends a message to the containing app and it shows a panel with last open tabs. This approach has a problem: it shows a message to a user in settings: "Can read sensitive info from web pages, including passwords..." Which is bad, because in reality i don't read passwords. If i remove SFSafariContentScript key in the Safari App Extension target's Info.plist, then this message about reading sensitive data disappears, but then i loose the ability to open the tabs panel. How can I open my app window with a shortcut without frightening a user? It's possible to listen to global key presses, but that would require a user to grant the app permissions of Accessibility (Privacy & Security) in macOS system settings, which also sounds shady. I know an app which does not require an Accessibility permission: https://apps.apple.com/ua/app/tabback-lite/id6469582909 and at the same time it does not tell a user about reading sensitive data in the extension settings. Here is my app: https://apps.apple.com/ua/app/tab-finder/id6741719894 It's open-source: https://github.com/kopyl/safari-tab-switcher

I’m encountering an issue with a Safari extension bundled with our main application (F-Secure). The extension is not appearing consistently in Safari settings on a customer’s iPad running iOS 18.3. Below are the details of the issue: Issue Description The Safari extension is bundled with the main app (F-Secure). After installing the app, the extension should automatically appear in Settings > Safari > Extensions, where the user can enable it. On the customer’s iPad, the extension is missing from the Safari settings. It briefly appeared once but then disappeared again.

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!

We’re encountering an issue when trying to add non-standard headers to outgoing requests using Declarative Net Request (DNR) rules in our Safari Web Extension. Tested on macOS 15.4 with Safari 18.4. Specifically, when attempting to add a custom header such as "X-Custom-Header" using a DNR rule, the header does not appear in the request. We are able to add standard headers like "Authorization" and "Cookie" to the request successfully using the same method. This behavior suggests that Safari may be filtering or blocking non-standard headers when set via DNR rules, unlike other browsers. In Chrome and Firefox, the same rule adds the "X-Custom-Header" header without any 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.

Can someone please help me: I do not have the brain space (85yo) to figure out an Apple Script or Java Script app to do this simple task. I have spent a few hours each day, over several days, and have made zero progress on such an apparently simple task. I wish to create an Automator App for the macOS Safari browser that will schedule (via a Calendar Event) the download of the 48hr data behind the hourly Fuel Mix Plot Data from the AEMO Web Site, every Monday, Wednesday, Friday and Sunday. Here is the link to the AEMO web site: AEMO, Energy Systems, Electricity, National Electricity Market (NEM), Data (NEM),Data Dashboard https://www.aemo.com.au/energy-systems/electricity/national-electricity-market-nem/data-nem/data-dashboard-nem The 48 hour hourly Fuel Mix data is found by selecting the "Fuel Mix" button (which by default will display the NEM Current Trend). The 48 hour trend is displayed by tapping on the small "Current" pulldown menu, and selecting "48 hrs". The 48hr Data is down loaded by selecting the small circular button just to the right of the pulldown menu. a) AEMO Web Site: https://www.aemo.com.au/energy-systems/electricity/national-electricity-market-nem/data-nem/data-dashboard-nem b) Main Menu, and underlying html, c) Fuel Mix menu, Pulldown list, DownLoad button, and underlying html, I am familiar with C++ and have built Xcode Apps, and used Excel Macros extensively in the past. Thank you. Robert.

Whenever I make a safari view controller on XCode26 Beta 5, there appears to be a blurry white overlay overtop the controller. This worked fine in XCode26 Beta 2, with no code differences. Anyone have any suggestions?

When I'm inspecting a WKWebView in a simulator and the WKWebView loads a local URL with a port number, I've found that most features of Safari dev tools that worked in iOS 17 are broken in iOS 18. Here are the steps I'm taking: Set up a WKWebView with isInspectable = true that loads a local URL, e.g. https://www.local.mydomain.com:3000 Install a self-signed SSL certificate on a simulator for www.local.mydomain.com Run my app on the simulator The WKWebView loads successfully In Safari on my Mac, I can select the WKWebView and open dev tools to inspect it If the simulator is on iOS 17, this works fine, no issues. But if the simulator is on iOS 18, Safari dev tools are mostly broken. I can tell that there is a connection to the WKWebView because the Network tab logs the requests that I expect. But I cannot use any of the other dev tools features: Elements, Sources, Console, etc. Has anyone else encountered this? Is there a workaround?

I am currently operating an app using an embedded web server that communicates over local HTTP. Recently, when opening Safari, I started encountering the following error message: "Safari cannot open the page. Error: Failed to navigate to an HTTP URL with HTTPS-only mode enabled." However, I am currently in a situation where switching to HTTPS is difficult. Are there any solutions to resolve this issue besides using HTTPS? Thank you.🙏

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.

I'm building a macOS extension that needs to track multi-step navigation chains (A → B → C) to adjust behavior based on where users came from. Current approach: Using webNavigation.onBeforeNavigate to detect intermediate steps, but experiencing issues in Safari that don't occur on Chrome/Firefox/Edge. Questions: Is webNavigation the right API for tracking redirect chains in Safari? Does ITP/Private Browsing affect event delivery? Any alternative approaches recommended? (Safari version 26.0.1) Any guidance appreciated!

From a mail app or similar, when opening a webpage in Safari as an external browser, JavaScript on the webpage stops running if Safari goes into the background. Is there a way to prevent this from happening? Sample code for the counter: Behavior: Upon returning from the background, the counter continues for about 7-8 seconds but does not progress further. For example, if Safari is kept in the background for about 20 seconds and then brought back, the counter stops at around 7-8 seconds and only resumes counting after returning to the foreground. Expectation: The counter should continue running even if Safari goes into the background.

I’m experiencing a crash in WKWebView on iOS 26 Developer Beta 5 and Beta 6 with the following exception: CALayer position contains NaN: [nan 65] The crash occurs when the following CSS properties are applied to content displayed in WKWebView: -webkit-user-select: none; -webkit-touch-callout: none; This issue happens consistently whenever these styles are set, leading to the crash inside WKWebView. Is this a known bug in the current iOS 26 betas, or is there a recommended workaround?

Hi everyone, I’m encountering a serious reliability issue with message passing in my Safari extension on iOS 18.4.1 and iOS 18.5 In my extension, I use the standard messaging API where the background script sends a message to the content scrip. The content script is listening using: browser.runtime.onMessage.addListener(handler); This setup has been working reliably in previous versions of iOS, but since updating to iOS 18.4.1 and iOS 18.5, I’ve noticed that messages sent from the background script are not consistently received by the content script. From my logs, I can confirm that: The background script is sending the message. The content script’s listener is not always triggered. There are no errors or exceptions logged in either script. It seems as if browser.runtime.onMessage.addListener is either not getting registered in time or failing silently in some instances. This issue is intermittent and does not occur all the time. Has anyone else experienced similar issues in iOS 18.4.1 and 18.5? Are there any known changes or workarounds for ensuring reliable communication between background and content scripts in this version? Any help or insights would be greatly appreciated. Thanks!

(related post: How to optimize my app for for a carrier-provided satellite network? ) I am trying to implement an app so that it works under a carrier-provided satellite network. The app uses (AS)WebAuthenticationSession for signing in. If the app is entitled to access a satellite network, will (AS)WebAuthenticationSession work as well? How about WKWebView and SFSafariViewController? Is there a way to test(simulate) a ultra-constrained network on a device or a simulator to see the expected behavior? Thanks,

We have a SAML-based SSO App Extension that uses WKWebView to load the SAML login request. This implementation has been working correctly on iOS versions prior to 26. However, starting with iOS 26, the extension consistently crashes when calling WKWebView.load(_:). The crash occurs inside WebKit, specifically in: /Library/Caches/com.apple.xbs/Sources/WebKit/Source/WebKit/UIProcess/WebsiteData/WebsiteDataStore.cpp at WebKit::WebPageProxy::loadRequest(...) No app-level exception is thrown, and the extension terminates with: Thread 10: EXC_BREAKPOINT (code=1, subcode=0x1a31dbe00) It appears that WKWebView initialization or WebsiteDataStore creation is now restricted in extension contexts on iOS 26, but this change is not documented in the SDK release notes. Could you please confirm if this is an intentional sandbox restriction in iOS 26 or a regression in WebKit? Steps to reproduce: Implement an App Extension using ASAuthorizationProviderExtensionAuthorizationRequest. Create a WKWebView instance in the extension. Attempt to load a SAML login request (POST request with headers). Observe immediate crash on iOS 26 (works fine on earlier versions). Expected behavior: WKWebView should load the request or fail gracefully as in prior releases, without crashing the extension process. Request: Please clarify if WKWebView usage inside extensions is officially unsupported as of iOS 26, and if so, recommend an alternative approach for handling SSO flows.

I have a basic setup following WWDC 2020 on Safari Web Extensions and another one on XPC. The video even mentions that one can use UserDefaults or XPC to communicate with the host app. Here is my setup. macOS 15.2, Xcode 16.2 A macOS app (all targets sandboxed, with an app group) with 3 targets: SwiftUI Hello World web extension XPC Service The web extension itself works and can update UserDefaults, which can then be read by SwiftUI app - everything works by the book. The app can communicate to the XPC service via NSXPCConnection - again, everything works fine. The problem is that the web extension does not communicate with XPC, and this is what I need so that I can avoid using UserDefaults for larger and more complex payloads. Web Ext handler code: class SafariWebExtensionHandler: NSObject, NSExtensionRequestHandling { func beginRequest(with context: NSExtensionContext) { // Unpack the message from Safari Web Extension. let item = context.inputItems[0] as? NSExtensionItem let message = item?.userInfo?[SFExtensionMessageKey] // Update the value in UserDefaults. let defaults = UserDefaults(suiteName: "com.***.AppName.group") let messageDictionary = message as? [String: String] if messageDictionary?["message"] == "Word highlighted" { var currentValue = defaults?.integer(forKey: "WordHighlightedCount") ?? 0 currentValue += 1 defaults?.set(currentValue, forKey: "WordHighlightedCount") } let response = NSExtensionItem() response.userInfo = [ SFExtensionMessageKey: [ "Response to": message ] ] os_log(.default, "setting up XPC connection") let xpcConnection = NSXPCConnection(serviceName: "com.***.AppName.AppName-XPC-Service") xpcConnection.remoteObjectInterface = NSXPCInterface(with: AppName_XPC_ServiceProtocol.self) xpcConnection.resume() let service = xpcConnection.remoteObjectProxyWithErrorHandler { error in os_log(.default, "Received error: %{public}@", error as CVarArg) } as? AppName_XPC_ServiceProtocol service?.performCalculation(firstNumber: 23, secondNumber: 19) { result in NSLog("Result of calculation XPC is: \(result)") os_log(.default, "Result of calculation XPC is: \(result)") context.completeRequest(returningItems: [response], completionHandler: nil) } } } The error I'm getting: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.***.AppName.AppName-XPC-Service was invalidated: failed at lookup with error 3 - No such process." What am I missing?

Hi there! I'm new to App Development and I'm running into the following error when playing audio on a website loaded through a WKWebView: 0x112000cc0 - ProcessAssertion::acquireSync Failed to acquire RBS assertion 'WebKit Media Playback' for process with PID=70.197, error: Error Domain=RBSServiceErrorDomain Code=1 "(originator doesn't have entitlement com.apple.runningboard.assertions.webkit AND originator doesn't have entitlement com.apple.multitasking.systemappassertions)" UserInfo={NSLocalizedFailureReason=(originator doesn't have entitlement com.apple.runningboard.assertions.webkit AND originator doesn't have entitlement com.apple.multitasking.systemappassertions)} Looking through this forum, it seems more people have this issue, yet no one has found a solution (or posted it...). The solutions that I did find (Background Modes capability, webView.configuration.allowsInlineMediaPlayback = true), did nothing. To make sure the issue had nothing to do with my own code, I created an empty project to reproduce the issue. I'm not sure on the best way to share it, but it's a small file (forgive me, I have no clue what it does, actually chatGPT made it for me. My real application is a WebApp wrapped with Capacitor, so it handles all the Swift stuff) import SwiftUI import WebKit struct WebView: UIViewRepresentable { let urlString: String func makeUIView(context: Context) -> WKWebView { let webView = WKWebView() webView.configuration.allowsInlineMediaPlayback = true webView.configuration.allowsAirPlayForMediaPlayback = true webView.navigationDelegate = context.coordinator return webView } func updateUIView(_ uiView: WKWebView, context: Context) { if let url = URL(string: urlString) { let request = URLRequest(url: url) uiView.load(request) } } func makeCoordinator() -> Coordinator { Coordinator(self) } class Coordinator: NSObject, WKNavigationDelegate { var parent: WebView init(_ parent: WebView) { self.parent = parent } func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) { print("Web page loading failed: \(error.localizedDescription)") } } } struct WebViewDemo: View { var body: some View { NavigationView { WebView(urlString: "https://www.w3schools.com/html/tryit.asp?filename=tryhtml5_audio_all") .navigationBarTitle("Web View") } } } struct WebView_Previews: PreviewProvider { static var previews: some View { WebViewDemo() } } Nothing special, right? When I build the app and navigate to a website that has an tag (https://www.w3schools.com/html/tryit.asp?filename=tryhtml5_audio_all). I still see the error when I play the audio. It plays nonetheless, but the error is there. I'm not at all interested in actually playing audio in the background/when the app is closed/suspended. I just want the error to go away! I've tried different iOS versions (14,15,16,17), but the problem persists. Anyone know what's happening?

I'm experiencing a Safari Web Extension issue where the non-persistant background script seems to crash after 30 seconds even when the content script is messaging it. Here is a minimal-reproducible example. When running in an emulator, the background script will stay responsive forever. However, when running on a physical device, the background script becomes non-responsive after 30 seconds of activity. It never becomes responsive again until I toggle the extensions enable/disable toggle, after which it stays active for 30 seconds and then crashes again.

We are experiencing an issue with Safari in all versions from 18.0 to 18.5 that does not occur in version 17. It affects both iPhones and Macs. And does not happen in Chrome or Windows. The problem is impacting our customers, and our monitoring tools show a dramatic increase in error volume as more users buy/upgrade to iOS 18. The issue relates to network connectivity that is lost randomly. I can reliably reproduce the issue online in production, as well as on my local development environment. For example our website backoffice has a ping, that has a frequency of X seconds, or when user is doing actions like add to a cart increasing the quantity that requires backend validation with some specific frequency the issue is noticable... To test this I ran a JS code to simulate a ping with a timer that calls a local-dev API (a probe that waits 2s to simulate "work") and delay the next HTTP requests with a dynamic value to simulate network conditions: Note: To even make the issue more clear, I'm using GET with application/json payload to make the request not simple, and require a Pre-flight request, which doubles the issue. (async () => { for (let i = 0; i < 30; i++) { try { console.log(`Request start ${i} ${new Date().toLocaleString()}`); const res = await fetch(`https://api.redated.com:8090/1/*****/probe?`, { method: 'GET', mode: "cors", //headers: {'Content-Type': 'text/plain'}, headers: { 'Content-Type': 'application/json' }, }); console.log(`Request end ${i} ${new Date().toLocaleString()} status:`, res.status); } catch (err) { console.error(`Request ${i} ${new Date().toLocaleString()} error:`, err); } let delta = Math.floor(Math.random() * 10); console.log("wait delta",delta); await new Promise(r => setTimeout(r, 1000 - delta)); } })(); For simplicity lets see a case where it fails 1 time only out of 10 requests. (Adjusting the "delta" var on the time interval create more or less errors...) This are the results: The network connection was lost error, which is false, since this is on my localhost machine, but this happens many times and is very reproducible in local and production online. The dev-tools and network tab shows empty for status error, ip, connection_id etc.. its like the request is being terminated very soon. Later I did a detailed debugging with safari and wireshark to really nail down the network flow of the problem: I will explain what this means: Frame 10824 – 18:52:03.939197: new connection initiated (SYN, ACK, ECE). Frame 10831 – 18:52:04.061531: Client sends payload (preflight request) to the server. Frame 10959 – 18:52:09.207686: Server responds with data to (preflight response) to the client. Frame 10960 – 18:52:09.207856: Client acknowledges (ACK) receipt of the preflight response. Frame 10961 – 18:52:09.212188: Client sends the actual request payload after preflight OK and then server replies with ACK. Frame 11092 – 18:52:14.332951: Server sends the final payload (main request response) to the client. Frame 11093 – 18:52:14.333093: captures the client acknowledging the final server response, which marks the successful completion of the main request. Frame 11146 – 18:52:15.348433: [IMPORTANT] the client attempts to send another new request just one second later, which is extremely close to the keep-alive timeout of 1 second. The last message from the server was at 18:52:14.332951, meaning the connection’s keep-alive timeout is predicted to end around 18:52:15.332951 but it does not. The new request is sent at 18:52:15.348433, just microseconds after the predicted timeout. The request leaves before the client browser knows the connection is closed, but by the time it arrives at the server, the connection is already dead. Frame 11147 – 18:52:15.356910: Shows the server finally sending the FIN,ACK to indicate the connection is closed. This happens slightly later than the predicted time, at microsecond 356910 compared to the expected 332951. The FIN,ACK corresponds to sequence 1193 from the ACK of the last data packet in frame 11093. Conclusions: The root cause is related to network handling issues, when the server runs in a setting of keep-alive behavior and keep-alive timeout (in this case 1s) and network timming issue with Safari reusing a closed connection without retrying. In this situation the browser should retry the request, which is what other browsers do and what Safari did before version 18, since it did not suffer from this issue. This behaviour must differ from previous Safari versions (however i read all the public change logs and could not related the regression change). Also is more pronounced with HTTP/1.1 connections due to how the keep-alive is handled. When the server is configured with a short keep-alive timeout of 1 second, and requests are sent at roughly one-second intervals, such as API pings at fixed intervals or user actions like incrementing a cart quantity that trigger backend calls where the probability of failure is high. This effect is even more apparent when the request uses a preflight with POST because it doubles the chance, although GET requests are also affected. This was a just a test case, but in real production our monitoring tools started to detect a big increment with this network error at scale, many requests per day... which is very disrupting, because user actions are randomly being dropped when the user actions and timming happens to be just near a previous connection, where keep alive timeout kicks-in, but because the browser is not yet notified it re-uses the same connection, but by the time it arrived the server is a dead connection. The safari just does nothing about it, does not even retry, be it a pre-flight or not, it just gives this error. Other browsers don't have this issue. Thanks!