Github url


by servo

servo /servo

The Servo Browser Engine

16.2K Stars 2.4K Forks Last release: Not found Mozilla Public License 2.0 42.7K Commits 5 Releases

Available items

No Items, yet!

The developer of this repository has not created any items for sale yet. Need a bug fixed? Help with integration? A different license? Create a request here:

The Servo Parallel Browser Engine Project

Linux Build StatusChangelog #228

Servo is a prototype web browser engine written in theRust language. It is currently developed on 64-bit macOS, 64-bit Linux, 64-bit Windows, and Android.

Servo welcomes contribution from everyone. See[

]( and [


]( help getting started.

Visit the Servo Project page for news and guides.

Setting up your environment

Building servo requires rustup, version 1.8.0 or more recent. If you have an older version, run

rustup self update


To install on Windows, download and run [


]( follow the onscreen instructions.

To install on other systems, run:

curl -sSf | sh

This will also download the current stable version of Rust, which Servo won’t use. To skip that step, run instead:

curl -sSf | sh -s -- --default-toolchain none

See also Other installation methods

Other dependencies

Please select your operating system: * macOS* Debian-based Linuxes* Fedora* Arch Linux* openSUSE* Gentoo Linux* Microsoft Windows* Android


Xcode version 10.2 or above is recommended.

On macOS (Homebrew)

NOTE: run these steps after you've cloned the project locally.

cd servo brew bundle install --file=etc/taskcluster/macos/Brewfile brew bundle install --file=etc/taskcluster/macos/Brewfile-build pip install virtualenv

On Debian-based Linuxes

sudo apt install python-virtualenv python-pip ./mach bootstrap


./mach bootstrap

doesn't work, file a bug, and, run the commands below:

sudo apt install git curl autoconf libx11-dev libfreetype6-dev libgl1-mesa-dri \ libglib2.0-dev xorg-dev gperf g++ build-essential cmake libssl-dev \ liblzma-dev libxmu6 libxmu-dev \ libgles2-mesa-dev libegl1-mesa-dev libdbus-1-dev libharfbuzz-dev ccache \ clang libunwind-dev libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev \ libgstreamer-plugins-bad1.0-dev autoconf2.13 llvm-dev

Additionally, you'll need a local copy of GStreamer with a version later than 12.0. You can place it in


, or run

./mach bootstrap-gstreamer

to set it up.

If you are using Ubuntu 16.04 or Linux Mint 18.* run


before building to avoid an error with harfbuzz.

If you get an undefined symbol error on


try removing


and all old versions of clang, see #22016

On Fedora

sudo dnf install python3 python3-virtualenv python3-pip python3-devel python3 ./mach bootstrap


python3 ./mach bootstrap

doesn't work, file a bug, and, run the commands below:

sudo dnf install curl libtool gcc-c++ libXi-devel libunwind-devel \ freetype-devel mesa-libGL-devel mesa-libEGL-devel glib2-devel libX11-devel \ libXrandr-devel gperf fontconfig-devel cabextract ttmkfdir expat-devel \ rpm-build openssl-devel cmake libX11-devel libXcursor-devel \ libXmu-devel dbus-devel ncurses-devel harfbuzz-devel \ ccache clang clang-libs python3-devel gstreamer1-devel \ gstreamer1-plugins-base-devel gstreamer1-plugins-bad-free-devel autoconf213

On CentOS

sudo yum install python-virtualenv python-pip ./mach bootstrap


./mach bootstrap

doesn't work, file a bug, and, run the commands below:

sudo yum install curl libtool gcc-c++ libXi-devel freetype-devel \ mesa-libGL-devel mesa-libEGL-devel glib2-devel libX11-devel libXrandr-devel \ gperf fontconfig-devel cabextract ttmkfdir python expat-devel rpm-build \ openssl-devel cmake3 libXcursor-devel libXmu-devel \ dbus-devel ncurses-devel python34 harfbuzz-devel \ ccache clang clang-libs llvm-toolset-7

Build inside





scl enable devtoolset-7 llvm-toolset-7 bash

with the following environmental variables set:

export CMAKE=cmake3 export LIBCLANG\_PATH=/opt/rh/llvm-toolset-7/root/usr/lib64

On openSUSE Linux

sudo zypper install libX11-devel libexpat-devel Mesa-libEGL-devel Mesa-libGL-devel cabextract cmake \ dbus-1-devel fontconfig-devel freetype-devel gcc-c++ git glib2-devel gperf \ harfbuzz-devel libXcursor-devel libXi-devel libXmu-devel libXrandr-devel libopenssl-devel \ python-pip python-virtualenv rpm-build ccache llvm-clang libclang autoconf213 gstreamer-devel \ gstreamer-plugins-base-devel gstreamer-plugins-bad-devel

On Arch Linux

sudo pacman -S --needed base-devel git python2 python2-virtualenv python2-pip mesa cmake libxmu \ pkg-config ttf-fira-sans harfbuzz ccache llvm clang autoconf2.13 gstreamer gstreamer-vaapi

On Gentoo Linux

sudo emerge net-misc/curl \ media-libs/freetype media-libs/mesa dev-util/gperf \ dev-python/virtualenv dev-python/pip dev-libs/openssl \ media-libs/harfbuzz dev-util/ccache sys-libs/libunwind \ x11-libs/libXmu x11-base/xorg-server sys-devel/clang \ media-libs/gstreamer media-libs/gst-plugins-bad media-libs/gst-plugins-base

With the following environment variable set:

sh export LIBCLANG\_PATH=$(llvm-config --prefix)/lib64

On Windows (MSVC)

  1. Install Python 2.7 for Windows ( The Windows x86-64 MSI installer is fine. This is required for the build system execution and many dependencies.

You should change the installation to install the "Add python.exe to Path" feature.

You will also need to set the


environment variable, e.g., to 'C:\Python27\python.exe' by doing:

setx PYTHON2 "C:\Python27\python.exe" /m
  1. Install Python 3.7 for Windows ( The Windows x86-64 MSI installer is fine. This is required in order to build the JavaScript engine, SpiderMonkey.

You will also need to set the


environment variable, e.g., to 'C:\Python37\python.exe' by doing:

setx PYTHON3 "C:\Python37\python.exe" /m



will set it system-wide for all future command windows.

  1. Install virtualenv.

In a normal Windows Shell (cmd.exe or "Command Prompt" from the start menu), do:

pip install virtualenv

If this does not work, you may need to reboot for the changed PATH settings (by the python installer) to take effect.

  1. Install the most recent GStreamer MSVC packages. You need to download the two
    files for your platform from the GStreamer website and install them. The currently recommended version is 1.16.0. i.e.:

Note that the MinGW binaries will not work, so make sure that you install the MSVC the ones.

Note that you should ensure that all components are installed from gstreamer, as we require many of the optional libraries that are not installed by default.

  1. Install Git for Windows ( DO allow it to add git.exe to the PATH (default settings for the installer are fine).

  2. Install Visual Studio Community 2017 ( You MUST add "Visual C++" to the list of installed components as well as the "Windows Universal C runtime." They are not on by default. Visual Studio 2017 MUST installed to the default location or mach.bat will not find it.

Note that version is hard to download online and is easier to install via Chocolatey with: ``` choco install -y visualstudio2017community --package-parameters="'--add Microsoft.VisualStudio.Component.Git'" Update-SessionEnvironment #refreshing env due to Git install

--- UWP Workload and installing Windows Template Studio ---

choco install -y visualstudio2017-workload-nativedesktop ```

[Optional] Install LLVM for faster link times

You may experience much faster builds on Windows by following these steps. (Related Rust issue:

  1. Download the latest version of LLVM (
  2. Run the installer and choose to add LLVM to the system PATH.
  3. Add the following to your Cargo config (Found at
    ). You may need to change the triple to match your environment.
[target.x86\_64-pc-windows-msvc] linker = "lld-link.exe"
Troubleshooting a Windows environment

If you encountered errors with the environment above, do the following for a workaround: 1. Download and install Build Tools for Visual Studio 20172. Install

python2.7 x86-x64


  1. Run
    mach.bat build -d

If you have troubles with

x64 type

prompt as


set by default: 1. You may need to choose and launch the type manually, such as

x86\_x64 Cross Tools Command Prompt for VS 2017

in the Windows menu.) 2.

cd to/the/path/servo
  1. python mach build -d

If you got the error

Cannot run mach in a path on a case-sensitive file system on Windows

: 1. Open Command Prompt or PowerShell as administrator. 2. Disable case-sensitive for servo path,

fsutil.exe file SetCaseSensitiveInfo X:\path\to\servo disable

If you got the error

DLL file


not found!

then set the


environment variable to an appropriate

Windows Kit

directory containing


, for example

C:\Program Files (x86)\Windows Kits\10


If you get the error

thread 'main' panicked at 'Unable to find libclang: "couldn\'t find any valid shared libraries matching: [\'clang.dll\', \'libclang.dll\'], set the


environment variable to a path where one of these files can be found (invalid: ... invalid DLL (64-bit))])"'



may have installed the 32-bit default target rather than the 64-bit one. You can find the configuration with

rustup show

, and set the default with rustup set default-host x86_64-pc-windows-msvc.

Cross-compilation for Android


./mach bootstrap-android --build

to get Android-specific tools. See wiki fordetails.

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[


]( file.


Servo is built with Cargo, the Rust package manager. We also use Mozilla's Mach tools to orchestrate the build and other tasks.

Normal build

To build Servo in development mode. This is useful for development, but the resulting binary is very slow.

git clone cd servo ./mach build --dev ./mach run tests/html/about-mozilla.html

Or on Windows MSVC, in a normal Command Prompt (cmd.exe):

cmd git clone cd servo mach.bat build --dev

For benchmarking, performance testing, or real-world use, add the


flag to create an optimized build:

./mach build --release ./mach run --release tests/html/about-mozilla.html


mach build

will build both




. To make compilation a bit faster, it's possible to only compile the servo binary:

./mach build --dev -p servo


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.

Building for Android target

For ARM (


, most phones):

./mach build --release --android ./mach package --release --android

For x86 (typically for the emulator):

./mach build --release --target i686-linux-android ./mach package --release --target i686-linux-android


Run Servo with the command:

./servo [url] [arguments] # if you run with nightly build ./mach run [url] [arguments] # if you run with mach # For example ./mach run

Commandline Arguments

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


There are lots of mach commands you can use. You can list them with

./mach --help


The generated documentation can be found on

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.