gecko-dev/testing/geckodriver

geckodriver

Proxy for using W3C WebDriver-compatible clients to interact with Gecko-based browsers.

This program provides the HTTP API described by the WebDriver protocol to communicate with Gecko browsers, such as Firefox. It translates calls into the Marionette automation protocol by acting as a proxy between the local- and remote ends.

You can consult the change log for a record of all notable changes to the program.

Supported Firefoxen

Marionette and geckodriver are not yet feature complete. This means it does not yet offer full conformance with the WebDriver standard or complete compatibility with Selenium.

You can track the implementation status of the latest Firefox Nightly on MDN. We also keep track of known Marionette, Selenium, and specification problems in our issue tracker.

Marionette support is best in Firefox 48 and onwards, although the more recent the Firefox version, the more bug fixes and features. Firefox 47 is explicitly not supported.

Firefox capabilities

geckodriver supports a capability named firefoxOptions which takes Firefox-specific preference values. This must be a dictionary and may contain any of the following fields:

Name	Type	Default	Description
binary	string	Taken from -b argument or system default location	Absolute path of the Firefox binary, e.g. /usr/bin/firefox or /Applications/Firefox.app/Contents/MacOS/firefox, to select which custom browser binary to use. If left undefined geckodriver will attempt to deduce the default location of Firefox on the current system.
args	Array.<string>		Command line arguments to pass to the Firefox binary. These must include the leading -- where required e.g. ["--devtools"].
profile	string	New, empty profile	Base64-encoded zip of a profile directory to use as the profile for the Firefox instance. This may be used to e.g. install extensions or custom certificates.
log	Log options object		Logging options for Gecko.
prefs	Object<string, (string|boolean|integer)>		Map of preference name to preference value, which can be a string, a boolean or an integer.

Log options

Name	Type	Default	Description
level	String	info with optimised Firefox builds, and debug with non-optimised	Set the level of verbosity in Gecko. Available levels are trace, debug, config, info, warn, error, and fatal.

Building

geckodriver is written in Rust and you need the Rust toolchain to compile it.

To build the project for release, ensure you do a compilation with optimisations:

% cargo build --release

Or if you want a non-optimised binary for debugging:

% cargo build

Usage

Usage steps are documented on MDN, but the gist of it is this:

% geckodriver -b /usr/bin/firefox

Or if you’re on Mac:

% geckodriver -b /Applications/FirefoxNightly.app/Contents/MacOS/firefox-bin