Deprecation of experimental CDP support in Firefox

[Henrik Skupin]

Hello all,

I would like to inform you about an important update regarding Firefox's experimental support for the Chrome DevTools Protocol (CDP). As detailed in our recent post (see the link below), Firefox will be deprecating CDP support in favor of the more feature-rich and robust WebDriver BiDi protocol.

Key Points:

- Deprecation of CDP: Starting with Firefox 129, CDP support will no longer be enabled by default. However, CDP can still be manually enabled by setting the Firefox preference `remote.active-protocols` to `2` before starting Firefox or by restarting the browser after updating the preference.

- Continued Support with ESR 128: For those relying on CDP, the Firefox 128 ESR release will maintain the current support for CDP for approximately one year until EOL for this extended support release, providing a smoother transition period.

- No Impact on Puppeteer Users: Puppeteer users will not be affected by the deprecation of CDP, as Puppeteer will automatically set the necessary preference based on the selected protocol (CDP or WebDriver BiDi).

- End of CDP Support: We plan to completely remove CDP support from Firefox by the end of 2024. If you have a client or tool that currently uses CDP and you wish to continue supporting Firefox, please notify us. This will help us keep you informed about future protocol changes.

For more detailed information, please read our full blog post.

If you have any questions or need assistance, feel free to reach out via the dev-webdriver mailing list or join the discussion on Matrix in the #webdriver channel. We are here to help and ensure a smooth transition to WebDriver BiDi.

Best regards,

Henrik Skupin

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Henrik Skupin
Staff Software Engineer
Mozilla Corporation