Building WebKit for iOS Simulator

Note: This post has been updated with a new tool for enabling Xcode to build command line tools.

I am proud to formally announce that you can now build and run top-of-tree WebKit for iOS in the iOS Simulator. We have updated the pages on with details on building for iOS Simulator. For your convenience, I have summarized the steps to get you up and running below:

  1. Install Xcode 6.1.1 or newer.
  2. Get the Code.
  3. Enable Xcode to build command line tools by running sudo Tools/Scripts/configure-xcode-for-embedded-development in the Terminal.
  4. Build WebKit for iOS Simulator by running Tools/Scripts/build-webkit --ios-simulator.
  5. Launch Safari in the iOS Simulator with the WebKit version you built by running Tools/Scripts/run-safari --ios-simulator.

Early Warning System (EWS) bots for iOS are running to help contributors catch build breakage before a patch is landed. The EWS bots build 32-bit iOS WebKit for ARMv7 hardware. We chose to build this configuration because it will most likely reveal build errors that differ from the configuration built by the existing Mac EWS bots.

We are working to bring up support for running layout tests, build and test build bots and additional iOS EWS configurations to help contributors notice build issues and regressions in WebKit for iOS.

We have always encouraged you to file all WebKit bugs that you find. Since upstreaming iOS WebKit to open source in early 2014, we have tracked iOS WebKit bugs in Now that you are able to build and run iOS WebKit yourself, we invite you to help fix them!