The Servo Parallel Browser Engine Project

See and for help getting started.

Build Setup

If these instructions fail or you would like to install dependencies manually, try the manual build setup.


  • Run ./mach bootstrap
    Note: This will install the recommended version of GStreamer globally on your system.


  • Run mach bootstrap
    • This will install CMake, Git, and Ninja via choco in an Administrator console. Allow the scripts to run and once the operation finishes, close the new console.
  • Run refreshenv

See also Windows Troubleshooting Tips.


  • Ensure that the following environment variables are set:
    • ANDROID_NDK_ROOT: $ANDROID_SDK_ROOT/ndk/25.2.9519653/
      ANDROID_SDK_ROOT can be any directory (such as ~/android-sdk). All of the Android build dependencies will be installed there.
  • Install the latest version of the Android command-line tools to $ANDROID_SDK_ROOT/cmdline-tools/latest.
  • Run the following command to install the necessary components:
    sudo $ANDROID_SDK_ROOT/cmdline-tools/latest/bin/sdkmanager --install
     "build-tools;33.0.2" \
     "emulator" \
     "ndk;25.2.9519653" \
     "platform-tools" \
     "platforms;android-33" \

For information about building and running the Android build, see the Android documentation.

The Rust compiler

Servo's build system uses to automatically download a Rust compiler. This is a specific version of Rust Nightly determined by the rust-toolchain.toml file.

Checking for build errors, without building

If you’re making changes to one crate that cause build errors in another crate, consider this instead of a full build:

./mach check

It will run cargo check, which runs the analysis phase of the compiler (and so shows build errors if any) but skips the code generation phase. This can be a lot faster than a full build, though of course it doesn’t produce a binary you can run.

Commandline Arguments

  • -p INTERVAL turns on the profiler and dumps info to the console every INTERVAL seconds
  • -s SIZE sets the tile size for painting; defaults to 512
  • -z disables all graphical output; useful for running JS / layout tests
  • -Z help displays useful output to debug servo

Keyboard Shortcuts

  • Ctrl+L opens URL prompt (Cmd+L on Mac)
  • Ctrl+R reloads current page (Cmd+R on Mac)
  • Ctrl+- zooms out (Cmd+- on Mac)
  • Ctrl+= zooms in (Cmd+= on Mac)
  • Alt+left arrow goes backwards in the history (Cmd+left arrow on Mac)
  • Alt+right arrow goes forwards in the history (Cmd+right arrow on Mac)
  • Esc or Ctrl+Q exits Servo (Cmd+Q on Mac)


The generated documentation can be found on