Ninja Build

Ninja is a build system written with the specific goal of improving the edit-compile cycle time. It is used by default everywhere except when building for iOS.

Ninja behaves very similar to Make -- the major feature is that it starts building files nearly instantly. (It has a number of minor user interface improvements to make as well.)

Read more about Ninja at the Ninja home page.

Using it

Configure your system to use Ninja


Ninja is included in depot_tools so there's nothing to install.

Build instructions

To build Chrome:

cd /path/to/chrome/src
ninja -C out/Debug chrome

Specify out/Release for a release build. I recommend setting up an alias so that you don't need to type out that build directory path.

If you want to build all targets, use ninja -C out/Debug all. It‘s faster to build only the target you’re working on, like chrome or unit_tests.


Identical to Linux, just make sure OS=android is in your GYP_DEFINES. You want to build one of the apk targets, e.g. content_shell_apk.


Similar to Linux. It uses MSVS's cl.exe, link.exe, etc. so you still need to have VS installed. To use it, open cmd.exe, go to your chrome checkout, and run:

set GYP_DEFINES=component=shared_library
python build\gyp_chromium
ninja -C out\Debug chrome.exe

component=shared_library is optional but recommended for faster links.

You can also set GYP_GENERATORS=ninja,msvs-ninja to get both VS projects generated if you want to use VS just to browse/edit (but then gyp takes twice as long to run).

If you‘re using Express or the Windows SDK by itself (rather than using a Visual Studio install), you’ll need to run from a vcvarsall command prompt.


Miss VS for debugging? /debugexe chrome.exe --my-great-args "go here" --single-process etc

Miss Xcode for debugging? Read

Without Visual Studio

That is, building with just the WinDDK. This is documented in the regular build instructions.


Building through errors

Pass a flag like -k3 to make Ninja build until it hits three errors instead of stopping at the first.


Pass a flag like -j8 to use 8 parallel processes, or -j1 to compile just one at a time (helpful if you're getting weird compiler errors). By default Ninja tries to use all your processors.

More options

There are more options. Run ninja --help to see them all.

Custom build configs

You can write a specific build config to a specific output directory via the -G flags to gyp. Here's an example from jamesr: build/gyp_chromium -Gconfig=Release -Goutput_dir=out_profiling -Dprofiling=1 -Dlinux_fpic=0


If you encounter any problems, please file a bug at with label ninja and cc thakis@ or scottmg@. Assume that it is a bug in Ninja before you bother anyone about e.g. link problems.