Firefox specific functionality
Selenium 4 requires Firefox 78 or greater. It is recommended to always use the latest version of geckodriver.
Options
Capabilities common to all browsers are described on the Options page.
Capabilities unique to Firefox can be found at Mozilla’s page for firefoxOptions
Starting a Firefox session with basic defined options looks like this:
Arguments
The args parameter is for a list of Command line switches used when starting the browser.
Commonly used args include -headless and "-profile", "/path/to/profile"
Add an argument to options:
Start browser in a specified location
The binary parameter takes the path of an alternate location of browser to use. For example, with this parameter you can use geckodriver to drive Firefox Nightly instead of the production version when both are present on your computer.
Add a browser location to options:
Profiles
There are several ways to work with Firefox profiles.
Note: Whether you create an emptyFirefoxProfile or point it to the directory of your own profile, Selenium will create a temporary directory to store either the data of the new profile or a copy of your existing one. Every time you run your program, a different temporary directory will be created. These directories are not cleaned up explicitly by Selenium, they should eventually get removed by the operating system. However, if you want to remove the copy manually (e.g. if your profile is large in size), the path of the copy is exposed by the FirefoxProfile object. Check the language specific implementation to see how to retrieve that location.If you want to use an existing Firefox profile, you can pass in the path to that profile. Please refer to the official Firefox documentation for instructions on how to find the directory of your profile.
Service
Service settings common to all browsers are described on the Service page.
Log output
Getting driver logs can be helpful for debugging various issues. The Service class lets you direct where the logs will go. Logging output is ignored unless the user directs it somewhere.
File output
To change the logging output to save to a specific file:
Console output
To change the logging output to display in the console:
Log level
There are 7 available log levels: fatal, error, warn, info, config, debug, trace. If logging is specified the level defaults to info.
Note that -v is equivalent to -log debug and -vv is equivalent to log trace, so this examples is just for setting the log level generically:
Truncated Logs
The driver logs everything that gets sent to it, including string representations of large binaries, so Firefox truncates lines by default. To turn off truncation:
Profile Root
The default directory for profiles is the system temporary directory. If you do not have access to that directory, or want profiles to be created some place specific, you can change the profile root directory:
Special Features
Some browsers have implemented additional features that are unique to them.
Add-ons
Unlike Chrome, Firefox extensions are not added as part of capabilities as mentioned in this issue, they are created after starting the driver.
The following examples are for local webdrivers. For remote webdrivers, please refer to the Remote WebDriver page.
Installation
A signed xpi file you would get from Mozilla Addon page
Uninstallation
Uninstalling an addon requires knowing its id. The id can be obtained from the return value when installing the add-on.
Unsigned installation
When working with an unfinished or unpublished extension, it will likely not be signed. As such, it can only be installed as “temporary.” This can be done by passing in either a zip file or a directory, here’s an example with a directory:
Full page screenshots
The following examples are for local webdrivers. For remote webdrivers, please refer to the Remote WebDriver page.
Context
The following examples are for local webdrivers. For remote webdrivers, please refer to the Remote WebDriver page.
Note: As of Firefox 138, geckodriver needs to be started with the argument --allow-system-access to switch the context to CHROME.