Closed Bug 1447419 Opened 6 years ago Closed 4 years ago

Miserable performance on


(Firefox for Android Graveyard :: General, defect, P5)

Firefox 60



Tracking Status
fennec ? ---


(Reporter: kael, Unassigned)

Details'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.
Hardware: Unspecified → All
Re-triaging per

Needinfo :susheel if you think this bug should be re-triaged.
Priority: -- → P5
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.
I have noticed the same behaviour on current (64.0b12) beta and nightly. Just browsing Twitter triggers very high cpu usage and even cpu overheat. Using standard top command via root access gives about 180% CPU with 320MB+ Ram on android 8.1 arm64.
We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly]( an issue can be reported at the [Fenix GitHub project]( If you want to discuss your report please use [Mozilla's chat]( server and join the [#fenix]( channel.
Closed: 4 years ago
Resolution: --- → INCOMPLETE
Product: Firefox for Android → Firefox for Android Graveyard
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