Closed Bug 1685629 Opened 2 years ago Closed 11 months ago

[Bug] Twitter behaving weirdly on firefox


(Web Compatibility :: Mobile, defect)



(Not tracked)



(Reporter: kbrosnan, Unassigned, NeedInfo)


From github:

Steps to reproduce

open twitter on firefox mobile scroll to a tweet which contains video, wait for it to autoplay

Expected behavior

video should play smoothly

Actual behavior

weird glitches

Device information

  • Android device: mido running on android 7 based on miui 11.0.2
  • Fenix version: 84.1.2
    the logcat:

Change performed by the Move to Bugzilla add-on.

Component: General → Mobile
Product: GeckoView → Web Compatibility

I'm reposting here a bug report that got wrongly closed with the migration of the new Firefox for Android to GitHub ("Miserable performance on",

That old bug actually seems to apply to Gecko/GeckoView and not the application, because the rendering issues are still happening after the transition to the new Firefox reimplementation.

Original report by :kael

(2018-03-20)'s performance is absolutely miserable in Android Firefox. Running Beta 60.0 from the Play Store on a Galaxy S8 Edge, connected to an enterprise-grade wifi AP on gigabit internet.

Initial page loads are pretty fast, and scrolling doesn't usually hitch up, but after the tab has been open for around a minute or more it typically takes 500ms+ to respond to any taps. Text input is even slower, I can easily type a word or two on the OS keyboard before any of it shows up in their text fields. The page layout also jitters around a lot on a very long delay - I'll scroll down, tap a retweet button, and watch for 2-3 seconds as the page layout jitters around and then it registers my tap on an entirely separate part of the page because the layout changed. I also frequently see blank areas when scrolling, and image embeds in tweets can sometimes take multiple seconds to appear once they scroll into view (in the interim they're solid colored boxes.)

I wouldn't be surprised if 100% of this is Twitter bugs but it's pretty nasty. In particular it seems awful that taps can go to a different element if the page layout changes in the 2000ms between my tap and the actual processing of the event - the compositor knows where the layers and/or elements were when I tapped, right?

I tried checking about:performance for info but it never finishes loading on Android.

Here's a screen recording:

When I tapped the like button a couple times each one took upwards of 1000ms to register. You can see slow loading of images and blank gaps as well. This is a fresh load of a mobile twitter tab.


fwiw this is still my user experience in Android Firefox for mobile twitter. Most other websites are fine. Happens for mobile data too. If I kill the Firefox process using Android's task switcher and restart, it's a little more responsive for a bit but once the page has been open for long enough it's bad again. (A hard refresh seems to help too).

The interaction between the lag and reflows is still pretty nasty as well - not sure if that counts as a separate issue or not, since fixing the bad responsiveness would make that issue basically nonexistent.

Complementary info from myself

  • Toggling Tracking Protection does not fix the issue.
  • Cannot reproduce in Chrome (or other non-Mozilla browser). While Twitter's Web UI responsiveness is far from ideal regardless of web browser, Chrome shows minimal issues with loading images, tweet contents, and overall interface elements.
  • Device information:
    • Android device: Xiaomi Redmi Note 4X, PixelExperience with Android 9.
    • Fenix version: version Nightly 210411 17:01. Tested a clean installation: No add-ons, no settings changed from default.

Needs Triage.

Flags: needinfo?(raul.bucata)
Flags: needinfo?(oana.arbuzov)

We appreciate your report. I was not able to reproduce the issue. Videos are played automatically when accessing the page.

Tested with:
Browser / VersionFirefox Nightly 92.0a1 (2015822291 -🦎92.0a1-20210715094037🦎)
Operating System: Samsung A51 (Android 11) -1080 × 2400 pixels 20:9 aspect ratio (~405 ppi density)

Suggestion: Try clearing cache/data/cookies, disable Ad-blocker (if available), or use a clean profile, and check again? If there are any changes made to the default settings of the browser (e.g. in about: config) please revert to the default settings and try again. Also, have the required cookies been accepted for this page? Also, is "Autoplay" option on default settings (e.g. if it set to "Block audio and video", then this is expected behaviour, the default setting is "Block audio only")

Flags: needinfo?(raul.bucata)
Flags: needinfo?(oana.arbuzov)
Flags: needinfo?(kbrosnan)

I am not the reporter. Please ask on GitHub for the reporter to confirm that this is still a problem.

Flags: needinfo?(kbrosnan)

Not the original reporter, either. But I can say that the issue is the overall experience on the website. While the specific issue of videos not autoplaying seems to work fine in most up-to-date versions of the browser, the general jankyness and slowness of the site is still perceived; basically what the original report title tries to say with "Twitter behaving weirdly on firefox".

The same kind of bad experience was also described by an older report that I reposted in this comment: which includes a link to a video that is still representative of what happens in current versions of the browser. In general I'd summarize it as global slowness in content loading. Apart from speed, I must say the visual glitches have been reduced by a lot in the last releases, but one that seems to remain is the weird positioning of videos during several seconds, when they are expanded to full screen.

This issue is a bit too broad to be able to diagnose.
Specifically when others can't reproduce. It could be performances of the device itself. It could be something else.
I'm tempted to close as INCOMPLETE as there are not enough details to reproduce it consistently.

  • Do you have to be logged-in?
  • Does it happen right away on any tweets with a video?
  • Is there a specific URI to test? Or does it happen on the homepage?
  • Is it happening on a different device in the same network context for the person?
  • The original bug was reported with Firefox 84. Is it happening with the latest release?
  • What is the status of ETP? (Strict, Basic?)
  • Does it happen with a more recent version of Android?

The logcat mentioned Failed to open, but that seems more Android related.

It's probably frustrating, but there's not much we can do.
I will close, but feel free to add comments and we may reopen.

Closed: 11 months ago
Flags: needinfo?(oneorjuan)
Resolution: --- → INCOMPLETE

It's OK I think that the experience has generally improved in later months, maybe due to improvements in Firefox, in the Twitter website code, or both. I'll provide more feedback if I'm able to isolate some more specific glitch or issue. Thanks.

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