Path to the Firefox binary to use. By default geckodriver tries to
find and use the system installation of Firefox, but that behaviour
can be changed by using this option. Note that the
capability of the
moz:firefoxOptions object that is passed when
creating a new session will override this option.
On Linux systems it will use the first firefox binary found
by searching the
PATH environmental variable, which is roughly
equivalent to calling whereis(1) and extracting the second column:
% whereis firefox firefox: /usr/bin/firefox /usr/local/firefox
On macOS, the binary is found by looking for the first firefox-bin
binary in the same fashion as on Linux systems. This means it is
possible to also use
PATH to control where geckodriver should
find Firefox on macOS. It will then look for /Applications/Firefox.app.
On Windows systems, geckodriver looks for the system Firefox by scanning the Windows registry.
Connect geckodriver to an existing Firefox instance. This means geckodriver will abstain from the default of starting a new Firefox session.
The existing Firefox instance must have [Marionette] enabled.
To enable the remote protocol in Firefox, you can pass the
-marionette flag. Unless the
has been user-set, Marionette will listen on port 2828. So when
--connect-existing it is likely you will also have to use
--marionette-port to set the correct port.
Host to use for the WebDriver server. Defaults to 127.0.0.1.
Set the Gecko and geckodriver log level. Possible values are
Selects the port for geckodriver’s connection to the [Marionette] remote protocol.
In the default mode where geckodriver starts and manages the Firefox
process, it will pick a free port assigned by the system and set the
marionette.port preference in the profile.
--connect-existing is used and the Firefox process is not
under geckodriver’s control, it will simply connect to PORT.
Port to use for the WebDriver server. Defaults to 4444.
A helpful trick is that it is possible to bind to 0 to get the system to atomically assign a free port.
Attach browser toolbox debugger when Firefox starts. This is useful for debugging [Marionette] internals.
Increases the logging verbosity by to debug level when passing
-v, or to trace level if
-vv is passed. This is
analogous to passing
--log debug and
--log trace, respectively.