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  1. d356276 Add bytes() to Blob and PushMessageData by Anne van Kesteren · 79 minutes ago main
  2. 083dc3e [WGSL] Function parameters have incorrect scope by Tadeu Zagallo · 2 hours ago
  3. 666a7c0 [WGSL] Struct arguments to entry points are clashing by Tadeu Zagallo · 2 hours ago
  4. 25ceab6 [Win] Link clang_rt.builtins in preparation for int128_t by Ross Kirsling · 3 hours ago
  5. c42e020 Web process sends redundant information when establishing GPU process connection by Kimmo Kinnunen · 6 hours ago


WebKit is a cross-platform web browser engine. On iOS and macOS, it powers Safari, Mail, iBooks, and many other applications. For more information about WebKit, see the WebKit project website.

Trying the Latest

On macOS, download Safari Technology Preview to test the latest version of WebKit. On Linux, download Epiphany Technology Preview. On Windows, you'll have to build it yourself.

Reporting Bugs

  1. Search WebKit Bugzilla to see if there is an existing report for the bug you've encountered.
  2. Create a Bugzilla account to report bugs (and comment on them) if you haven't done so already.
  3. File a bug in accordance with our guidelines.

Once your bug is filed, you will receive email when it is updated at each stage in the bug life cycle. After the bug is considered fixed, you may be asked to download the latest nightly and confirm that the fix works for you.

Getting the Code

Run the following command to clone WebKit's Git repository:

git clone WebKit

Building WebKit

Building for Apple platforms

Install Xcode and its command line tools if you haven't done so already:

  1. Install Xcode Get Xcode from To build WebKit for OS X, Xcode 5.1.1 or later is required. To build WebKit for iOS Simulator, Xcode 7 or later is required.
  2. Install the Xcode Command Line Tools In Terminal, run the command: xcode-select --install

Run the following command to build a macOS debug build with debugging symbols and assertions:

Tools/Scripts/build-webkit --debug

For performance testing, and other purposes, use --release instead.

Embedded Builds

To build for an embedded platform like iOS, tvOS, or watchOS, pass a platform argument to build-webkit.

For example, to build a debug build with debugging symbols and assertions for embedded simulators:

Tools/Scripts/build-webkit --debug --<platform>-simulator

or embedded devices:

Tools/Scripts/build-webkit --debug --<platform>-device

where platform is ios, tvos or watchos.

Using Xcode

You can open WebKit.xcworkspace to build and debug WebKit within Xcode. Select the “Everything up to WebKit + Tools” scheme to build the entire project.

If you don't use a custom build location in Xcode preferences, you have to update the workspace settings to use WebKitBuild directory. In menu bar, choose File > Workspace Settings, then click the Advanced button, select “Custom”, “Relative to Workspace”, and enter WebKitBuild for both Products and Intermediates.

Building the GTK Port

For production builds:

cmake -DPORT=GTK -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
sudo ninja install

For development builds:

Tools/Scripts/build-webkit --gtk --debug

For more information on building WebKitGTK, see the wiki page.

Building the WPE Port

For production builds:

cmake -DPORT=WPE -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
sudo ninja install

For development builds:

Tools/Scripts/build-webkit --wpe --debug

Building Windows Port

For building WebKit on Windows, see the WebKit on Windows page.

Running WebKit

With Safari and Other macOS Applications

Run the following command to launch Safari with your local build of WebKit:

Tools/Scripts/run-safari --debug

The run-safari script sets the DYLD_FRAMEWORK_PATH environment variable to point to your build products, and then launches /Applications/ DYLD_FRAMEWORK_PATH tells the system loader to prefer your build products over the frameworks installed in /System/Library/Frameworks.

To run other applications with your local build of WebKit, run the following command:

Tools/Scripts/run-webkit-app <application-path>

iOS Simulator

Run the following command to launch iOS simulator with your local build of WebKit:

run-safari --debug --ios-simulator

In both cases, if you have built release builds instead, use --release instead of --debug.

Linux Ports

If you have a development build, you can use the run-minibrowser script, e.g.:

run-minibrowser --debug --wpe

Pass one of --gtk, --jsc-only, or --wpe to indicate the port to use.


Congratulations! You’re up and running. Now you can begin coding in WebKit and contribute your fixes and new features to the project. For details on submitting your code to the project, read Contributing Code.