| Blog | https://fxdx.dev/ |
| Documentation | https://firefox-source-docs.mozilla.org/devtools-user/ |
| Contribute | https://firefox-source-docs.mozilla.org/devtools/ |
State of CSS 2025 is now open: https://stateofcss.com/
Browser vendors use the results of 'State of' surveys to help prioritize the features to work on.
If you care about CSS, please take some time to answer it, and help shape the future of the language
Oops, we forgot to share the WebDriver news for Firefox 138!
WebDriver BiDi now lets you install unsigned extensions and allows to set a default viewport for user contexts: https://fxdx.dev/firefox-webdriver-newsletter-138/
Firefox 139 introduces geolocation override via WebDriver BiDi!
Now you can easily test location-aware features: https://fxdx.dev/firefox-webdriver-newsletter-139/
CDP is removed in Firefox 141 in favor of WebDriver BiDi.
For details see https://fxdx.dev/cdp-retirement-in-firefox/
#Firefox 138 is around the corner, did you noticed some of the changes we made in 137? Find out in our latest blog post: https://fxdx.dev/firefox-devtools-newsletter-137/
and since I'm late (as always you might say), you get a bonus post from @juliandescottes talking about the new network request override feature: https://fxdx.dev/network-override-in-firefox-devtools/
Makes it way easier to debug code in prod!
#Firefox 138 is around the corner, did you noticed some of the changes we made in 137? Find out in our latest blog post: https://fxdx.dev/firefox-devtools-newsletter-137/
TIL that the most recent Firefox will now show the font licensing information in the inspector. Nice!
Exciting news: we're shipping Temporal in Firefox 139! Temporal is a new API for working with dates and times in JS.
This is a very large feature and our implementation was contributed by a single volunteer.
Read about it in our blog post: https://spidermonkey.dev/blog/2025/04/11/shipping-temporal.html
Firefox Nightly
Colin M. Ford
SpiderMonkey