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.
Explore 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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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
I'd like to know the install state of my iOS safari extension in the associated swift app. Is there any way to get this? As we have seen it is available for macOS here, is there anyway to know iOS Safari extension is enabled or not?
Thanks
Summary
Recently a number of bugs affecting our Safari extension have been introduced with various Safari 18.X updates. We've submitted feedback for all of these, but most have received no response. We need to raise this to your attention as it has been affecting our developer experience and causing a lot of frustration for our users. It's something that adds a lot of uncertainty for us. These issues affect core web functionalities but seem to be isolated to the Start Page or Extension environments.
For example:
using window.open, no longer works
using window.location.href = ... no longer works
Including a tag in our start page causes infinite reloading to occur.
registering a content script more than once will crash Safari
Details
Unable to open new window as as start page extension in Safari 18
FB15879470
What happens: Calling window.open does nothing. This broke our links to our feedback submission, marketing site & help site.
When: Nov 18, 2024 - Initial launch of Safari 18 on macOS
Status: Open, No response
Unable to open app url scheme with window.location.href in start page extension in iOS 18
FB15879596
What happens: Changing the URL in this way does nothing (well actually it does work about 10% of the time). This broke our navigation to in app payment.
When: Nov 18, 2024 - Initial launch of Safari 18 on iOS
Status: Open, No response
New tab extensions broken
FB16126043
What happens: Having a tag in your causes an infinite loop of reloading the start page. This broke our entire start page extension.
When: Dec 19, 2024 - Safari 18.3 on iOS beta
Status: 10 similar tickets found, marked for future OS update. We did get a response and a fix is identified for a future release
window.open opens “about:blank” when called from Start Page extension.
FB16427985
What happens: calling window.open from the start page opens about blank on iOS 18.3. Similar to the first issue, but slightly different behaviour. This broke our links to our feedback submission, marketing site & help site.
When: Jan 30, 2025 - Safari 18.3
Status: Open, No response
Registering a content script more than once causes Safari to crash in macOS 15.4 beta
FB16831768
What happens: We have an optional content script that we were registering every time it was used. Although somewhat redundant, it was much simpler than checking if one was already registered and tracking if an updated one needed to replace it. This works fine on all other browsers and all prior Safari versions we've released it on. However if a user enables site blocker on the latest version, as soon as they visit any website, our content script registration causes Safari to crash. Essentially preventing users from using Safari until they uninstall our extension.
When: Mar 11, 2025 - Safari 18.4
Status: Open, No response
In Conclusion
Luckily we have been able to isolate and find workarounds for most of these issues so far, but we are not guaranteed to in the future. We are raising this not only to have these issues looked into, but to raise awareness of the rising trend of basic functionality of Safari extensions breaking with Safari updates. We hope that this can influence a shift in your QA & feedback intake practices to ensure these issues are less frequent in the future.
We are happy to raise future issues through your provided channels as they are discovered. But to have our feedback ignored and then have to rely solely on workarounds to prevent disruptions to our users' experience is concerning.
We submitted this feedback to our developer relations contact, and he suggested we submit a TSI to look into these issues. In response to this, we were advised to post this here.
Summary:
We are facing a serious issue on iPhone where multiple passkey authentication problems occur when accessing passkey-enabled login pages via shortcuts placed on the iPhone Home Screen. These issues may also occur when opening the same pages directly in a standard browser window. However, launching the login pages from a Home Screen shortcut appears to increase the likelihood of encountering these issues.
Affected Services (examples, not exhaustive):
Amazon
GitHub
Adobe
Observed Issues:
Issue 1: A passkey authentication dialog/popup shows two times without any user operation:
What happens due to this issue:
Login does not complete after the first passkey authentication.
A second passkey authentication UI automatically appears.
Completing or canceling the second authentication allows the login to proceed.
Issue 2: Login remains stuck until the user manually invokes passkey again
What happens due to this issue:
The login page does not advance after the first authentication.
The user must tap the ID/username field again to manually trigger the passkey UI.
Completing the second authentication enables login.
Issue 3: Automatic second authentication occurs, but login still fails
What happens due to this issue:
A second automatic authentication UI appears.
Login still does not complete.
Tapping the ID field no longer opens the passkey UI; instead, the password auto-fill panel appears.
Passkey login becomes impossible.
Observed reproduction steps (not guaranteed but most consistently observed):
On iPhone, navigate to a passkey-enabled login page (e.g., Amazon, GitHub, Adobe) using a browser.
Create a shortcut from the browser's share menu and place it on the Home Screen.
Launch the login page from the Home Screen shortcut.
Tap the ID/username field to invoke the passkey prompt.
Complete passkey authentication.
→ One of the issues described above occurs.
Environment:
Device: iPhone SE
OS: iOS 18.6.2
Topic:
Safari & Web
SubTopic:
General
Tags:
WebKit
Safari
Safari and Web
Passkeys in iCloud Keychain
I don't know why but all of a sudden when I build the extension it just doesn't load in Safari. The build executes fine but the extension doesn't load. Sometimes, through trying different combinations of clearing the build folder, building, archiving, ... it suddenly loads. And the next time I build again it doesn't load properly. So I can't do any work on it or test anything.
I don't know why all of a sudden I am getting this behavior. It looks like engineers at Apple are constantly trying to overcomplicate a process that is at least ten times simpler in any other browser. This is ridiculous. Is this what our annual fee goes to? And they don't even provide any support for that. Several times I've tried to get some help here just to have to spend hours upon hours to figure it out by myself. I'm so tired of this.
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
I am using the native SwiftUI WebView and WebPage APIs (iOS 26+) and would like to implement file download functionality using the native SwiftUI WebView. However, I have not been able to find any APIs equivalent to WKDownload.
In WKWebView, the WKDownload API can be used to handle downloads. I am looking for a similar API or recommended approach in the native SwiftUI WebView that would allow downloading files.
If anyone has guidance or suggestions on how to implement this, I would appreciate your help.
I would like to know if there is a way to disable Smart Punctuation from the webpage rather than requiring the user to do so from the settings. Adding a "inputmode=verbatim" attribute to the input HTML tags for my webpage did that for all the web browsers I tested on Windows, Ubuntu, Android, and MacOS. I tested Chrome and Firefox on all platforms, as well as Edge on Windows and Safari on Mac and iOS. So far the only time it did not disable Smart Punctuation was on Safari on iOS, but it did on MacOS.
Hello everyone,
I am currently working on integrating a WebView into my macOS application, intended to allow users to browse tutorial webpages directly within the app.
Although I’ve followed an example that appears syntactically correct, the WebView does not render any webpage content.
Below is a code snippet for reference:
import SwiftUI
import WebKit
struct HelpWebView: View {
@State private var toggle = false
@State private var page = WebPage()
private var url: URL {
toggle
? URL(string: "https://www.webkit.org")!
: URL(string: "https://www.swift.org")!
}
var body: some View {
WebView(page)
.onAppear {
page.load(URLRequest(url: url))
}
.onChange(of: toggle) {
page.load(URLRequest(url: url))
}
.toolbar {
Button("Reload", systemImage: "arrow.clockwise") {
toggle.toggle()
}
}
}
}
I would greatly appreciate any insights or suggestions on what might be causing this issue or how to resolve it.
Thank you in advance for your help!
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.
In WKWebView, there is the WKUIDelegate method:
func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {}
This delegate method provides a callback when a new window (for example, target="_blank") is requested in the web view.
However, in native SwiftUI (iOS 26), WebView / WebPage APIs do not provide an equivalent delegate method to handle new window requests.
As a workaround, I am using the following method:
public func decidePolicy(for action: WebPage.NavigationAction, preferences: inout WebPage.NavigationPreferences) async -> WKNavigationActionPolicy {}
In this method, when action.target == nil, I treat it as a new window request.
My question:
Is relying on action.target == nil in decidePolicy a reliable and future-safe way to detect new window requests in SwiftUI’s WebView, or is there a better or more recommended approach for handling target="_blank" / new window navigation in the SwiftUI WebView APIs?
Code:
public func decidePolicy(for action: WebPage.NavigationAction, preferences: inout WebPage.NavigationPreferences) async -> WKNavigationActionPolicy {
guard let webPage = webPage else { return .cancel }
// Handle case where target frame is nil (e.g., target="_blank" or window.open)
// This indicates a new window request
if action.target == nil {
print("Target frame is nil - new window requested")
// WORKAROUND: Until iOS 26 WebPage UI protocol is available, we handle new windows here
// Try to create a new WebPage through UI plugins
if handleCreateWebPage(for: webPage, navigationAction: action) != nil {
// Note: The new WebPage has been created and published to the view
return .allow
}
}
return .allow
}
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
}
}
After App uses Network.framework PrivacyContext Api, dns has been encrypted, that is good.
But when using wkwebview to load web page, wireshark captures normal dns request sent by wkwebview.
Does wkwebview use DoH to resolve domain? if can, how to config params?
If can not, is there anyway to stop wkwebview sending normal dns, such as local proxy.
Hello,
I'm experiencing an issue where WKWebView consistently fails to load a specific URL on the iOS 18.4 simulator (Xcode 16.3). The error is as follows:
Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."
UserInfo={
_kCFStreamErrorCodeKey=-4,
_kCFStreamErrorDomainKey=4,
NSUnderlyingError=Error Domain=kCFErrorDomainCFNetwork Code=-1005,
NSErrorFailingURLKey=[REDACTED]
}
Key Observations:
This URL fails consistently only on the iOS 18.4 simulator.
The same URL loads without issue in iOS 18.3 and 18.2 simulators.
The backend is serving a valid HTTPS certificate chain, and the server appears to be presenting it properly.
The same application appears to work on a real iPhone running 18.4.
Certificate Chain for the Failing URL
Leaf: WR3 (Valid: Mar 17, 2025 – Jun 15, 2025)
Intermediate 1: GTS Root R1 (Valid: Dec 13, 2023 – Feb 20, 2029)
Intermediate 2: GlobalSign Root CA (Valid: Jun 19, 2020 – Jan 28, 2028)
Other URLs Work Fine in iOS 18.4 Simulator
WKWebView successfully loads the following URLs with similar or more complex certificate chains:
https://google.com → WR2, GTS Root R1, GlobalSign Root CA
https://amazon.com → DigiCert Global CA G2, DigiCert Global Root G2, VeriSign G5
https://stackoverflow.com → E5, ISRG Root X1
https://shopify.com → GlobalSign Root CA, GTS Root R4, WE1
This suggests the issue may not be with general network or certificate trust but instead something specific about how iOS 18.4 handles this domain or certificate configuration in the simulator.
Any insights on how to solve this would be greatly appreciated.
Is it possible to open the native app from a web extension?
I have tried creating a new tab that uses the app's URL scheme but the UI asking the user to open the app is not shown until the new page UI is dismissed.
Creating a tab with an HTTPS URL that the app is setup to handle does not work and always the link in a new tab.
I tried sending a message to the app extension and using NSExtensionContext.open(_:completionHandler:) but the URL is not opened and the closure received false, indicating it was not handled.
Having the option to link back to the native app would be very useful.
Sometimes Safari is rendering the icon for an active extension in its original provided colored representation, other times Safari is applying an overlay color in line with the system's highlight color.
This difference can even be seen seen on the Safari Extensions Developer home page: https://developer.apple.com/safari/extensions/images/extensions-hero-large_2x.png
You will notice that Grammarly's icon is shown in it's original color format, while the others aren't.
Example of extensions where the icon is shown in color:
Bitwarden
Grammarly
1Password
Consent-O-Matic
I've compared the source code of Bitwarden and Consent-o-Matic with my own extension and cannot find any differences in the settings or image properties (resolution, DPI, file type, color profile). If I take the exact PNG source files from said open source extensions and replace them in my own source code, these icons show up in full color.
Does this perhaps mean there is a bug in Safari's processing of the icons where it fails to overlay the icon with the highlight color in some cases?
I and I assume many developers with me would like to understand what determines this difference. Ideally, there is a consistent UX where the end user has the choice between icons in color or highlight color overlay.
My iOS app uses a WKWebView with a WKUIDelegate method (webView:createWebViewWithConfiguration:forNavigationAction:windowFeatures:) to handle popup windows. This works for most cases, but during OAuth flows on certain sites (e.g., canva.com), the popup WKWebView attempts to send results back to the main WKWebView using JavaScript like window.opener.postMessage(...). However, window.opener is always null in the popup, preventing the message from being posted and blocking login completion.I've researched this and found suggestions that it's by design, as WKWebView instances are isolated for security reasons. Has anyone encountered this and found a reliable workaround (e.g., bridging communication between the main and popup WKWebViews without relying on window.opener)?
Hello WebKit Team,
I’m writing to ask if iOS provides a native way to intercept AJAX (XMLHttpRequest or fetch) calls inside WKWebView.
On Android, this is handled via:
shouldInterceptRequest(WebView view, WebResourceRequest request)
but iOS currently seems to have no equivalent.
We’ve tried:
WKURLSchemeHandler → works only for custom schemes
URLProtocol with WKProcessPool → unreliable for AJAX in WebView
JavaScript injection → partial and unofficial
Could you please clarify:
Is there a recommended native approach to intercept AJAX requests?
If not supported, is it planned for future releases?
Any official workaround or guidance?
This is critical for debugging, analytics, and compliance in hybrid apps.
在 iOS 平台使用 WKWebView 通过file://协议加载本地 HTML 文件时,存储在localStorage中的数据会在 App 后台切换、进程重启后偶尔丢失;但相同代码在安卓 / 鸿蒙平台无此问题。
现在的文档
仅明确了「默认数据存储(defaultDataStore)可将网站数据持久化到磁盘,非持久化存储(nonPersistent)仅存内存」的基础规则;
未提及「file://协议内容即使使用默认持久化存储,也会被归为临时内存存储」这一关键场景限制;
仅在WKURLSchemeHandler关联说明中隐含「自定义 URL 协议可处理 WebKit 原生不支持的 URL 方案」,但未直接关联file://的存储问题。
我找不到如何处理这个问题的官方文档,仅仅有其他的博客说需要增加http/https加载就没有这个问题。
请提供给我官方文档或者官方回复 关于出现这种file:/加载html出现问题的处理办法