Mozilla acknowledges Firefox 139.0 'artifacting' bug, shares temporary workaround

Some Firefox users found their Browse experience unexpectedly disrupted by visual glitches after updating to the latest version, 139.0. A recent post on Reddit from a user described the problem as “artifacting.”

The issue seemed particularly prominent on pages laden with multiple media embeds, such as YouTube, Facebook, Instagram, and Reddit. One user on Reddit, rthreeohone, described the browser as “spazzing out” whenever such content was present. This wasn’t an isolated incident. Another user, cryamiga, elaborated on the visual disturbance:

Same here. It looks like it’s rendering as it reflows all the positions of the html elements and so lots of stuff flickering all over the place.

One user even shared a video highlighting the problem. Check it out:

The visual anomalies led some to initially suspect failing hardware. A user, Jalau, confessed, “Same issue, thought my GPU was dieing or something. Happy it’s just Firefox glitching out.” The common thread quickly became apparent: the problems started right after the Firefox 139.0 update. For many, other browsers like Chrome continued to work flawlessly, pointing the finger squarely at the recent Firefox release.

Users also noted that the artifacting seemed more pronounced in specific display setups. Several affected individuals mentioned using multiple monitors, particularly those running at different resolutions and refresh rates. One user, boboduflachi, stated:

Having the same issue. Only doing it on my high refresh monitor…Never had this issue in the past.

Mozilla employees actively engaged with the community under the post to understand the scope and cause of the problem. Thanks to user-submitted regression reports, which help pinpoint the exact software change that introduced a bug, Mozilla was able to narrow down the source.

In response, Mozilla has officially acknowledged the issue. The problem predominantly affects Windows users who have certain NVIDIA graphics adapters and are using multiple monitors with mixed refresh rates. The company has updated the release notes for Firefox 139.0 to include this known issue.

While a permanent fix is in the works and expected to be rolled out in an upcoming release, Firefox 139.0.1, Mozilla has provided a temporary workaround. Affected users can navigate to about:config in their Firefox address bar (a settings page for advanced preferences). From there, they should search for the preference gfx.webrender.dcomp-win.enabled and set its value to false. Restarting the browser after this change should alleviate the artifacting. Some users also reported that disabling hardware acceleration in Firefox settings offered relief, though Mozilla’s specific about:config tweak is the more targeted solution for this particular bug.

So for now, affected users have a way to continue using Firefox while awaiting the next patch.