Is ServiceWorker supported on WKWebView? As per Mozilla Developer Network(MDN Web) docs[1] its not supported, but our research shows that ServiceWorker becomes available for a domain in WKWebView 1) if the domain is allowlisted in app-bound domains[2] or 2) if app is registered as default browser(this can not be considered for our app as its not a browser).
How to enable ServiceWorker on WKWebView? Is adding domain as app-bound domain the right/only way to enable ServiceWorker on WKWebView? We didn't find any official documentation about this.
Can WebView get ServiceWorker support by default without enabling app bound domains since that is not an option for our app? Our app needs to support more than 10 domains. Powerful APIs such as JavaScript injection, cookie manipulation, event handlers are by default available to all domains/WebView instances even if App doesn't enable app-bound domains. Is it possible to do same for ServiceWorker?
If ServiceWorker can not be supported by default then can Apple provide a feature by which ServiceWorker will be enabled in App for all the domains?
Apple enforces maximum of 10 app-bound domains. Is it possible to remove this limit and provide a way to dynamically add to this list at the time of a request?
[1] https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorker#browser_compatibility
[2] https://webkit.org/blog/10882/app-bound-domains/
General
RSS for tagExplore the integration of web technologies within your app. Discuss building web-based apps, leveraging Safari functionalities, and integrating with web services.
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Hi,
I'm encountering an issue with the Clipboard API's writeText() method in Safari. It throws a NotAllowedError even when triggered by a user action (selecting an option from a <select> element). Is this expected?
This issue seems specific to Safari, as the same code works perfectly in Firefox and Chrome.
Perhaps I should send feedback to Apple, but I'd like to post it here first in case I misunderstand something.
Problem
In Safari, when I try to copy text to the clipboard using navigator.clipboard.writeText() within an input event listener attached to a <select> element, it fails with the following error:
NotAllowedError: The request is not allowed by the user agent or the platform in the current context, possibly because the user denied permission.
Environment
Safari
18.2 (20620.1.16.11.8)
Technology Preview 210
macOS Sequoia 15.2 (24C101)
Example
I've created a minimal reproducible example on CodePen: https://codepen.io/mshibanami/pen/LEPdxXZ
Here's the relevant JavaScript code from the example:
selectElement.addEventListener('input', async (event) => {
const selectedText = event.target.options[event.target.selectedIndex].text;
try {
await navigator.clipboard.writeText(selectedText);
alert(`Text copied to clipboard: ${selectedText}`);
} catch (err) {
alert('Failed to copy text to clipboard: ' + err);
}
});
Firefox and Chrome handle this code without any issues, successfully copying the text to the clipboard, but not Safari.
Possible Cause
I suspect this issue might be related to WebKit's User Activation API. It seems like Safari is not correctly recognizing the input or change event on a <select> element as a valid user activation for the Clipboard API, even though it is initiated by a user gesture.
Questions
Is this behavior unexpected? Should Safari allow the Clipboard API to work in this context?
(Technically, this might be expected as of now, as such events are not explicitly described in https://webkit.org/blog/13862/the-user-activation-api/.)
Any insights or suggestions would be greatly appreciated. Thanks!
When CHIPS was introduced in 18.4 it worked well, however on 18.5 it does not appear to work. There do not appear to be release notes about this in 18.5, so can someone provide definitive if this is a defect that will be fixed, or have they already been deprecated?
Title: Content Overlapping Address Bar After Clicking Links in Safari, tested on iPhone 11 (iOS 18.1.1)
Description:
When browsing in Safari on iPhone (iOS 18.1.1), the one-tab bar (address bar) collapses as expected when scrolling down a page. However, after clicking on a link and loading the next page, the content appears to overlap the collapsed address bar. This results in parts of the content being hidden or obscured by the address bar, which affects the user experience, especially on mobile devices with limited screen space. This issue is reproducible on Next.js applications and can be observed on websites such as rotterdam.nl and halderberge.nl.
Steps to Reproduce:
Enable the One-Tab Bar: Go to Settings > Safari and enable the one-tab bar feature.
Open the website rotterdam.nl or halderberge.nl in Safari on an iPhone 11 (iOS 18.1.1).
Scroll down the page so that the top address bar collapses.
Click on any link on the page to load a new one.
Once the new page loads, observe that the content appears on top of the collapsed address bar, causing parts of the content to be hidden or obscured.
Expected Result:
The content should not overlap or be hidden behind the collapsed address bar after the page reloads. The layout should adjust properly without interference from the address bar, providing a smooth user experience.
Actual Result:
When the new page loads, the content overlaps or appears on top of the collapsed address bar, causing parts of the content to be hidden or obscured.
Device(s) Affected:
iPhone 11 running iOS 18.1.1.
OS Version:
iOS 18.1.1
Technical Notes:
To address this issue, the following solutions have been attempted with no success:
Viewport Meta Tag:
<meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover" />
This was added to help ensure proper layout on mobile devices, but did not resolve the issue.
CSS Safe Area Insets:
body {
padding-top: env(safe-area-inset-top);
}
This CSS rule was applied to account for the safe area and prevent content from being hidden under the address bar, but it did not solve the overlapping issue.
Scroll Position Adjustment (for scroll-to-top button):
Adjusting the scroll behavior by changing the scroll position to {top: 1} instead of {top: 0} was a successful workaround to keep the address bar collapsed when clicking the "scroll to top" button. However, this did not resolve the issue when navigating between pages or changing routes, where the content still overlaps the collapsed address bar.
iOS Safari 18.4/18.5 with IIS Windows Authentication with negotiate hangs after entering credentials
I don't think the issue is specific iOS 18.
We have a web application that runs with IIS Authentication of Windows and Anonymous. Initially the app opens and the user clicks a button and triggers the "401 Challenge" via ASP.NET. The browser presents the Active Directory login, user enters credentials, clicks Sign In, and the browser hangs (may actually be negotiating something). After a few minutes the user is logged into the application.
We have done a number of google searches/AI to try to determine what to change and there is no clear solution. Is there anything else to try?
This problem is not seen in Chrome on iOS or on a Windows machine. Strangely it is also not seen using BrowserStack with one of their "real" devices.
We have other apps that run with just Windows Authorization and this problem is not observed.
Topic:
Safari & Web
SubTopic:
General
I am creating a Safari Web Extension.
There are two calls let say, call1 and call2 which gets executed in sequence by browser, call1 gives a 302 type response and redirects to call2.
When creating DNR rule for adding "Cookie" in the request header of call1, the same cookie gets added to the request header of call2 as well(Same is the case for other headers/custom headers as-well). Because of this the set-cookie present in response header of call1 is not sent in the request header of call2, and returns 400 response.
The same setting is working fine for other browsers chrome & firefox.
Is this a bug or DNR works differently for safari ?
currently "webRequestBlocking" works in safari for manifest v3, is there any development of it getting removed just like it's removed in chrome in mv3.
Hey Guys
My PWA video playback and even youtube videos stopped working after updating iOS to 26.0.1.
The video thumnails appear fine and if i try to play the video, it remains stuck.
If i restart the phone, the video plays for a second in the PWA and then stops again and entire app gets stuck.
Request apple team to fix this issue at the earliest. This is hampering all my iOS users who install the PWA on their device homescreen and use it as app.
FYI strangely EVERYTHING WORKS FINE ON iOS SAFARI browser including videos playback If i open it as a web app.
so this seems like a specific PWA issue on latest ios 26.0.1
Topic:
Safari & Web
SubTopic:
General
The issue of fixed elements with
{ bottom: 0 }
moving up when scrolling still persists.
It seems to be a general issue with the IOS 26 release.
It affects other browser too. I tested on browsers such as Safari, Chrome, Firefox, Edge and Bravo.
With the exception of Edge, all the others display the behavior.
Device: iPhone 15 Pro
IOS Version: 26.0.1
This is my first post, so please forgive me if it is to the wrong area.
I've been using Tahoe for a few days and, overall, it's very stable. But the one thing that has bothered me to no end is Safari's new behavior with respect to its header (Address bar, Favorite bookmarks bar, tab bar) background color. The web content of the active tab seems to affect everything - and oftentimes makes things completely unreadable - at least in "Dark" mode. For instance, if a web page uses a white background, the Favorites bookmark labels are the same color as the bookmark background, so reading the labels is simply impossible. At other times, they're just very difficult to read.
Similarly, it is almost always impossible to tell which tab is the active one - my only workaround is to try 100% brightness....or to just guess.
When Apple previously experimented with letting content bleed through to the top, there was a setting for stopping it - but I don't see such a setting anymore. Do you you know of any way to stop this effect?
Hi everyone,
I'm exploring the new app icon appearance options (Clear, Dark, Tinted) for Progressive Web Apps (PWAs) on iOS26, iPadOS26, and macOS26. Currently, PWA icons don't seem to render well with these new appearances, particularly in Clear and Tinted modes, resulting in very very poor visual quality. You can hardly see anything.
Has support for these icon appearances been fully implemented for PWAs? If so, could someone point me to the relevant Apple Developer documentation or provide guidance on how to configure PWA icons to support Clear, Dark, and Tinted appearances? I've searched the Apple Developer Forums, Stack Overflow, and Reddit but haven't found clear information on this topic.A possible solution is a png file with transparent areas, but if the pattern is dark, nothing will be visible in dark mode.
Any insights or resources would be greatly appreciated. Thanks!
(plz don't give up on PWA😭)
Reference:
https://developer.apple.com/forums/thread/761615
https://stackoverflow.com/questions/78780916/is-there-a-way-to-provide-light-dark-and-tinted-variants-of-apple-touch-icon
https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html
I'm a web developer of WebRTC based web app for video and audio calls. After updating to iOS 26.1 beta I noticed, that my app can't use microphone anymore.
When I'm calling to getUserMedia with audio set to true, Safari returns error "No AVAudioSessionCaptureDevice device".
Other WebRTC demo apps also can't access microphone on this firmware.
And maybe it's connected somehow, but safari can't detect connected AirPods Pro 2 as an input device.
So, this bug brakes any WebRTC app, that uses microphones.
I'm testing web extension to safari on iOS. I've built and added extension application to simulator, but on safari settings shows no extensions.
I'm using Xcode 16.3 beta 2 with Simulator iOS 18.4 (22E5216h), tested on iPhone 16.
https://app.screencast.com/oUq4EMonmfT7u
https://app.screencast.com/MCquvHzmZi8QS
I'm developing a web extension for Safari on iOS using MV3.
The extension is working fine in Chrome, but in Safari I experience some seemingly random issues. I would like to debug it, but here is my problem.
I have my iPhone connected via cable to Mac, and it works fine with XCode, so I assume this part is OK.
I open Safari or Safari Tech Preview (doesn't matter) on my Mac, developers options are enabled, and in the Develop menu, under my iPhone section, there are things I can debug. There is an entry "[Ext name] - Extension Service Worker" but when I click it, it's empty. Web inspector pops up, but there are no network requests, no logs, nothing. I know the extension is working, because I can stream log to my HTTP server, but I don't see them here at all. I can use console to trigger commands like chrome.storage.local.get(null, console.log) and it shows my local store, so why I don't see any logs? Also, the background script is not visible in the Sources tab, just one weird request:
navigator.serviceWorker.register('safari-web-extension://E3449EA7-EC25-4696-8E6C-[ID HERE]/background.js');
</script>
Any ideas what went wrong? The entire team of 4 people has the same issue and we can't move forward because of that.
Also, the Develop => Service workers or any other menu section doesn't show my service worker. Logs for websites running on my phone are visible and in general web inspector for them works fine.
Adding Stack Trace for your reference:
thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BREAKPOINT (code=1, subcode=0x1a6efe5b8)
frame #0: 0x00000001a6efe5b8 WebCoreWebCore::BaseAudioSharedUnit::BaseAudioSharedUnit() + 668 frame #1: 0x00000001a6efe044 WebCoreWebCore::CoreAudioSharedUnit::singleton() + 80
frame #2: 0x00000001a9521fe4 WebCoreWebCore::CoreAudioCaptureSource::create(WebCore::CaptureDevice const&, WebCore::MediaDeviceHashSalts&&, WebCore::MediaConstraints const*, std::__1::optional<WTF::ObjectIdentifierGeneric<WebCore::PageIdentifierType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long long>, unsigned long long>>) + 360 frame #3: 0x00000001a94f180c WebCoreWebCore::RealtimeMediaSourceCenter::getUserMediaDevices(WebCore::MediaStreamRequest const&, WebCore::MediaDeviceHashSalts&&, WTF::Vector<WebCore::RealtimeMediaSourceCenter::DeviceInfo, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>&, WTF::Vector<WebCore::RealtimeMediaSourceCenter::DeviceInfo, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>&, WebCore::MediaConstraintType&) + 356
frame #4: 0x00000001a94f22cc WebCoreWebCore::RealtimeMediaSourceCenter::validateRequestConstraintsAfterEnumeration(WTF::Function<void (WTF::Vector<WebCore::CaptureDevice, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>&&, WTF::Vector<WebCore::CaptureDevice, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>&&)>&&, WTF::Function<void (WebCore::MediaConstraintType)>&&, WebCore::MediaStreamRequest const&, WebCore::MediaDeviceHashSalts&&) + 356 frame #5: 0x00000001a94fb394 WebCoreWTF::Detail::CallableWrapper<WebCore::RealtimeMediaSourceCenter::enumerateDevices(bool, bool, bool, bool, WTF::CompletionHandler<void ()>&&)::$_0, void>::~CallableWrapper() + 164
frame #6: 0x00000001a814bbe8 WebCoreWTF::Detail::CallableWrapper<WebCore::AVCaptureDeviceManager::refreshCaptureDevicesInternal(WTF::CompletionHandler<void ()>&&, WebCore::AVCaptureDeviceManager::ShouldSetUserPreferredCamera)::$_0::operator()()::'lambda'(), void>::call() + 520 frame #7: 0x00000001ab7f1aac JavaScriptCoreWTF::RunLoop::performWork() + 524
frame #8: 0x00000001ab7f1880 JavaScriptCoreWTF::RunLoop::performWork(void*) + 36 frame #9: 0x00000001935e7d0c CoreFoundationCFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 28
frame #10: 0x00000001935e7ca0 CoreFoundation__CFRunLoopDoSource0 + 172 frame #11: 0x00000001935e6a24 CoreFoundation__CFRunLoopDoSources0 + 232
frame #12: 0x00000001935e5c64 CoreFoundation__CFRunLoopRun + 840 frame #13: 0x000000019360a730 CoreFoundationCFRunLoopRunSpecific + 572
frame #14: 0x00000001e0fb5190 GraphicsServicesGSEventRunModal + 168 frame #15: 0x0000000196239f34 UIKitCore-[UIApplication _run] + 816
frame #16: 0x0000000196238164 UIKitCore`UIApplicationMain + 336
frame #17: 0x000000010811bec4 AppName.debug.dylibmain at AppDelegate.swift:25:13 frame #18: 0x00000001bae06a58 dyldstart + 5964
Safari 18.2 on Sequoia 15.2 sends repeated Authorization header when iCloud Relay is enabled and the page is reloaded.
Inside Safari Preferences -> Privacy -> Hide IP address -> from Trackers and Websites (ensure this is enabled)
Visit a website that uses HTTP Authorization and authenticate oneself
Reload website a couple of times and it will result in an HTTP 400 error due to repeat Authorization header sent by Safari
Our team has implemented a video player using the HTML5 tag, but we have identified an issue with loading media files.
While Safari on iOS 18.0 downloads each TS file listed in the m3u8 playlist correctly, on iOS 18.4 and 18.5, a single TS file is downloaded repeatedly.
Our statistics indicate that approximately six requests are made per second for the same TS file.
Is this intended behavior?
If not, are there any known workaround or solutions?
If this issue is due to the OS or browser, are there any plans to address it in iOS 18.6 or a future release?
Could you advise on the proper channel to submit a bug report for this issue?
Similar issues have been reported in the past with WKWebView.
The previous thread is here:
https://developer.apple.com/forums/thread/784134
Topic:
Safari & Web
SubTopic:
General
Dear Apple Developer Experts,
We're experiencing an intermittent issue with WKWebView in our macOS application where local HTML file access is occasionally denied by the sandbox, despite proper implementation and permissions. We seek your guidance in understanding and resolving this issue.
Issue Description:
The WKWebView occasionally fails to load local HTML files stored in the app's Contents/Resources directory
Error occurs in WebKit Networking Process with sandbox denial
Issue is intermittent and can be resolved by app restart or WebKit Networking Process restart
Affects all local HTML files in the same directory once the issue occurs
Technical Details:
Error from Kernel Log:
2025-02-07 14:57:17.179821 +0800 kernel Sandbox: com.apple.WebKit.Networking(58661) deny(1) file-read-data /Applications/DingTalk.app/Contents/Resources/webcontent/contact-2024.html
WKWebView Delegate Error (captured in WKNavigationDelegate method):
(void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error
Error Details:
Domain: NSPOSIXErrorDomain
Code: 1
Description: "Operation not permitted"
UserInfo: {
networkTaskMetricsPrivacyStance: Unknown,
_NSURLErrorFailingURLSessionTaskErrorKey: LocalDataTask <3694CA1E-481B-4E06-975D-E3A56AD56C0F>.<1>,
_kCFStreamErrorDomainKey: 1,
_kCFStreamErrorCodeKey: 1
}
Key Observations:
Error is captured in WKNavigationDelegate's didFailProvisionalNavigation method
The issue affects all local HTML files in the same directory once it occurs
Temporary workarounds we've discovered:
Restarting the application completely resolves the issue
Without restarting the application, terminating the "WebKit Networking Process" via Activity Monitor causes the process to automatically restart, and this resolves the issue and load works again
Additional Information:
We've collected complete system diagnostics (system_logs.logarchive) at the time of failure
The issue appears similar to discussions in Apple Developer Forums (https://developer.apple.com/forums/thread/110072), though we're uncertain if it's the same root cause
We've prepared a minimal demo project demonstrating:
Our release version app can be downloaded from: https://dtapp-pub.dingtalk.com/dingtalk-desktop/mac_dmg/Release/M1-Beta/DingTalk_v7.6.45_43521682_universal.dmg?spm=0.0.0.0.UuwovG&file=DingTalk_v7.6.45_43521682_universal.dmg for examining our app's codesign, sandbox, and entitlements configurations if needed
Important Investigation Finding:
We attempted to simulate the issue by using chmod 000 /path/to/test.html, but this produces a different error:
CopyError Domain=NSURLErrorDomain
Code=-1102
Description="You do not have permission to access the requested resource."
UserInfo={
NSLocalizedDescription=You do not have permission to access the requested resource.,
NSErrorFailingURLStringKey=file:///Users/sunus/Library/Developer/Xcode/DerivedData/WKWebViewLocalDemo-eumardnlfbmwgnhkaadglsrrhzhs/Build/Products/Debug/WKWebViewLocalDemo.app/Contents/Resources/test.html,
NSUnderlyingError=0x600003aedc50 {Error Domain=kCFErrorDomainCFNetwork Code=-1102 "(null)"}
}
This error is distinctly different from our original issue's "Operation not permitted" error, suggesting that the sandbox denial we're experiencing is not a simple file permission issue.
Questions:
Is this a known issue with the WebKit sandbox in recent macOS versions?
Are there recommended best practices or workarounds to prevent this sandbox denial?
Could this be related to the WebKit Networking Process's sandbox configuration?
Are there additional diagnostics or logs we should collect to help investigate this issue?
We appreciate your assistance in investigating this issue. Please let us know if you need any additional information or clarification.
STEPS TO REPRODUCE
Open App
Then loads the local file in /WKWebViewLocalDemo.app/Contents/Resources/test.html
PS, We also submit a DTS & Feedback
DTS:Case-ID: 11876957
Feedback-ID: FB16493282
sysdiagnose is in the Feedback-ID: FB16493282 is uploaded
Since Xcode 26 our tests are crashing due to the Main Thread not being able to deallocate WKNavigationResponse.
Following an example:
import Foundation
import WebKit
final class WKNavigationResponeMock: WKNavigationResponse {
private let urlResponse: URLResponse
override var response: URLResponse { urlResponse }
init(urlResponse: URLResponse) {
self.urlResponse = urlResponse
super.init()
}
convenience init(httpUrlResponse: HTTPURLResponse) {
self.init(urlResponse: httpUrlResponse)
}
convenience init?(url: URL, statusCode: Int) {
guard let httpURLResponse = HTTPURLResponse(url: url, statusCode: statusCode, httpVersion: nil, headerFields: nil) else {
return nil
}
self.init(httpUrlResponse: httpURLResponse)
}
}
import WebKit
import XCTest
final class ExampleTests: XCTestCase {
@MainActor func testAllocAndDeallocWKNavigationResponse() {
let expectedURL = URL(string: "https://galaxus.ch/")!
let expectedStatusCode = 404
let instance = WKNavigationResponeMock()
// here it should dealloc/deinit `instance` automatically
}
Here the call stack:
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 CoreFoundation 0x101f3dd54 CFRetain.cold.1 + 16
1 CoreFoundation 0x101e14860 CFRetain + 104
2 WebKit 0x10864dd24 -[WKNavigationResponse dealloc] + 52
Hi,
I am developing an OpenType font with the following cursive feature.
feature curs {
lookup cursivejoinrtl; # RIGHT_TO_LEFT flag set between Hah, Meem, Yeh and final Meem
lookup rehwawcursive; # RIGHT_TO_LEFT flag clear between Waw and Hah
} curs;
Here is the rendering of the word وحميم in TextEdit.
Using HarfBuzz I got the following result.
The same rendering problem occurs when using Safari. It seems that is related to Core Text.
I reported the issue to Feedback Assistant over a year ago but haven't had a response yet. So I'm posting the problem on this forum.
Any support on this matter would be greatly appreciated.
Hello,
In iOS 26 beta, we are seeing an unexpected behavior when using SwiftUI WebView (or a custom WKWebView via UIViewRepresentable).
When an alert is presented above the WebView, the WebView immediately reloads to its initial page. The alert itself also disappears instantly, making it impossible for the user to interact with it.
This issue occurs both with the new SwiftUI WebView / WebPage API and with a wrapped WKWebView. The problem was not present in previous iOS versions (iOS 17/18).
Steps to reproduce:
Create a SwiftUI view with a WebView (pointing to any URL).
Add a toolbar button that toggles a SwiftUI alert.
Run the app on iOS 26 beta.
Tap the button to trigger the alert.
Expected behavior:
The WebView should remain as-is, and the alert should stay visible until the user dismisses it.
Actual behavior:
As soon as the alert appears, the WebView reloads and resets to the initial page. The alert disappears immediately.
Minimal Example:
struct ContentView: View {
@State private var showAlert = false
var body: some View {
NavigationStack {
WebView(URL(string: "https://apple.com")!)
.toolbar {
ToolbarItem(placement: .topBarTrailing) {
Button("Close") {
showAlert = true
}
}
}
.alert("Confirm close?", isPresented: $showAlert) {
Button("Cancel", role: .cancel) {}
Button("Close", role: .destructive) {}
}
}
}
}
I'm using Xcode Version 26.0 beta 7
Thanks for your help.