Running Blimp

See build for instructions on how to build Blimp.

Android Client

Installing the client

Install the Blimp APK with the following:

./build/android/ $(PRODUCT_DIR)/apks/Blimp.apk

This is equivalent to just running:

adb install $(PRODUCT_DIR)/apks/Blimp.apk

Setting up command line flags

Set up any command line flags with:

./build/android/adb_blimp_command_line --your-flag-here

To see your current command line, run adb_blimp_command_line without any arguments.

The Blimp client reads command line arguments from the file /data/local/blimp-command-line and the above script reads/writes that file. Typical format of the file is chrome --your-flag-here. So one can use adb directly to create the file:

echo 'chrome --engine-ip= --engine-port=25467 --engine-transport=tcp' \
  '--blimp-client-token-path=/data/data/org.chromium.blimp/blimp_client_token' \
  '--vmodule="*=1""' > /tmp/blimp-command-line
adb push /tmp/blimp-command-line /data/local/blimp-command-line
adb shell start chmod 0664 /data/local/blimp-command-line

Instructing client to connect to specific host

To have the client connect to a custom engine use the --engine-ip, --engine-port, and --engine-transport flags. The possible valid values for --engine-transport are ‘tcp’ and ‘ssl’. An example valid endpoint would be --engine-ip= --engine-port=25467 --engine-transport=tcp.

SSL-encrypted connections take an additional flag --engine-cert-path which specifies a path to a PEM-encoded certificate file (e.g. --engine-cert-path=/path_on_device_to/file.pem). Remember to also copy the file to the device when using this option.

Requesting the complete page from the engine

The engine sends partially rendered content to the client. To request the complete page from the engine, use the --download-whole-document flag on the client.

Specifying the client auth token file

The client needs access to a file containing a client auth token. One should make sure this file is available by pushing it onto the device before running the client. One can do this by running the following command:

adb push /path/to/blimp_client_token \

To have the client use the given client auth token file, use the --blimp-client-token-path flag (e.g. --blimp-client-token-path=/data/data/org.chromium.blimp/blimp_client_token)

An example of a client token file is test_client_token.

Start the Client

Run the Blimp APK with:


The script under the cover uses adb to start the application:

adb shell am start -a android.intent.action.VIEW -n org.chromium.blimp/org.chromium.blimp.BlimpRendererActivity

Connecting to an Engine running on a workstation

To run the engine on a workstation and make your Android client connect to it, you need to forward a port from the Android device to the host, and also instruct the client to connect using that port on its localhost address.

Port forwarding

If you are running the engine on your workstation and are connected to the client device via USB, you'll need remote port forwarding to allow the Blimp client to talk to your computer.

Option A

Follow the remote debugging instructions to get started. You'll probably want to remap 25467 to “localhost:25467”. Note This requires the separate Chrome application to be running on the device. Otherwise you will not see the green light for the port forwarding.

Option B

If you are having issues with using the built-in Chrome port forwarding, you can also start a new shell and keep the following command running:

./build/android/ --debug -v 25467 25467

Running the client in an Android emulator

Running the client using an Android emulator is similar to running it on device. Here are a few gotchas:

  • Build an APK matching the emulator cpu type. The emulator cpu type is most likely x86, while the default Android build cpu type is ARM. Follow the Android build instructions above to change the CPU type.

  • Ensure that the emulator is running at least Android Marshmallow so that fonts are rendered correctly. Also ensure that you have the latest Play services binaries.

  • Some of scripts under build/android will fail to run as it uses adb scp. Follow the instruction above to use adb directly.

  • To connect to an Engine running on the host machine, you should use as engine-ip instead of as will refer to the emulator itself. There is no need of set up port forwarding when this approach is used.

Linux Client

The Linux client is used for development purpose while the Android client is shipped. The Linux client is built as part of the blimp target. To run it with local logging enabled, execute:

./out-linux/Debug/blimp_shell \
  --user-data-dir=/tmp/blimpclient \
  --enable-logging=stderr \

Running the engine

In a container

For running the engine in a container, see container.

On a workstation

The following flags are required to start an Engine instance:

  • --blimp-client-token-path=$PATH: Path to a file containing a nonempty token string. If this is not present, the engine will fail to boot.
  • --use-remote-compositing: Ensures that the renderer uses the remote compositor.
  • --disable-cached-picture-raster: Ensures that rasterized content is not destroyed before serialization.
  • --android-fonts-path=$PATH: Path to where the fonts are located. Typically this would be out-linux/Debug/gen/third_party/blimp_fonts.
  • --disable-remote-fonts: Disables downloading of custom web fonts in the renderer.

Typical invocation

One can start the engine using these flags:

out-linux/Debug/blimp_engine_app \
  --android-fonts-path=out-linux/Debug/gen/third_party/blimp_fonts \
  --blimp-client-token-path=/tmp/blimpengine-token \
  --enable-logging=stderr \