WebKit Playground

Build an open-source version of WebKit and replace it system-wide on iOS jailbroken devices.

• Mobile Safari
• 3rd-party browsers (e.g. Chrome, Firefox, Edge)
• WKWebView
• UIWebView (i.e. WebKitLegacy)

Compatibility

WebKit Tag	Tested on iOS	Xcode Version	iOS SDK Version	Patch File
releases/Apple/Safari-16.1-iOS-16.1 (cherry-picks required)	16.1	14.1	16.1	webkit_iOS_16.3.1-worktree-20260412-004539.patch
	16.1.1
	16.1.2
releases/Apple/Safari-16.2-iOS-16.2	16.2	14.2	16.2
releases/Apple/Safari-16.3-iOS-16.3.1	16.3.1
releases/Apple/Safari-16.4-iOS-16.4.1	16.4.1	14.3.1	16.4	webkit_iOS_16.4.1-worktree-20260411-143740.patch
releases/Apple/Safari-16.5-iOS-16.5	16.5
	16.5.1

How to use

1. We need to patch dyld to allow DYLD_FRAMEWORK_PATH to work on top of DSC
2. Check out source code of WebKit and apply patches
3. Compile WebKit with the following command:

Tools/Scripts/build-webkit --ios-device --release --use-ccache \
WK_USE_CCACHE=YES \
ARCHS='arm64 arm64e' \
ONLY_ACTIVE_ARCH=NO \
GCC_TREAT_WARNINGS_AS_ERRORS=NO \
OTHER_CFLAGS='$(inherited) -Wno-error' \
OTHER_CPLUSPLUSFLAGS='$(inherited) -Wno-error'

4. Push compiled frameworks to /Library/Frameworks or $JBROOT/Library/Frameworks (RootHide).

Verify Replacement

Use User-Agent to verify that replaced WebKit is active:

1. Build/apply the patch and deploy frameworks to target device.
2. Open Safari (or any WKWebView host app) and visit a UA echo page (for example: https://httpbin.org/user-agent).
3. Confirm the returned User-Agent contains WKDebugUA/1.0.

If WKDebugUA/1.0 is present, traffic is using the replaced WebKit build from this repo.

Troubleshooting

iOS 16.1 required cherry-picks

When building releases/Apple/Safari-16.1-iOS-16.1 for iOS device, apply these 4 commits first:

git cherry-pick --no-gpg-sign \
21349d858b6b \
60cfd7b1e096 \
b594a5e7e91a \
d09b8b302cad

Patch Xcode SDK

If build fails with 'objc/objc-runtime.h' file not found, run:

sudo Tools/Scripts/configure-xcode-for-embedded-development

Build parallelism

If you want to increase compile/build parallelism globally in Xcode, run:

defaults write com.apple.dt.Xcode IDEBuildOperationMaxNumberOfConcurrentCompileTasks 48
defaults write com.apple.Xcode PBXNumberOfParallelBuildSubtasks 48

What they do:

• IDEBuildOperationMaxNumberOfConcurrentCompileTasks: controls the max number of concurrent compile tasks.
• PBXNumberOfParallelBuildSubtasks: controls the number of parallel PBX build subtasks in the build graph.

Notes:

• These are global user defaults and affect Xcode-driven builds on this machine.
• Restart Xcode after changing these values.
• To restore defaults:

defaults delete com.apple.dt.Xcode IDEBuildOperationMaxNumberOfConcurrentCompileTasks
defaults delete com.apple.Xcode PBXNumberOfParallelBuildSubtasks