2081346 - Firefox for Android unexpectedly closes during extended browsing sessions

Status: UNCONFIRMED

(Firefox for Android :: General, defect)

Description

[kominops]

User Agent: Mozilla/5.0 (Android 16; Mobile; rv:159.0) Gecko/159.0 Firefox/159.0

Steps to reproduce

1. Open Firefox for Android and navigate to Reddit (or other social media website).
2. Browse Reddit normally for an extended period.
3. Open multiple posts in new tabs and navigate between subreddits and user profiles.
4. After browsing for some time, Firefox unexpectedly closes and returns to the device's home screen.
5. Reopen Firefox. The browser returns to its homepage (expected behavior with open homepage at launch setting), and the previous browsing session appears to have been interrupted (tabs load fresh when going to them)

Actual results

Firefox for Android unexpectedly terminates while I am actively browsing. The app can be reopened, but the interruption disrupts the browsing session. The issue is intermittent and does not appear to be caused by manually closing the app. I checked Firefox's crash reports in settings, but no reports were listed. I have experienced this on Firefox versions 157 and 158 as well.

Device Info: Motorola G86 Power 5G, Android 16
Firefox versions: Release and Beta

Expected results

Firefox should remain open during normal browsing and should only close when I explicitly exit the app or when Android terminates it for battery saving.

Comment 1

[kominops]

It happened on new session too.

Comment 2

[twhite]

Thanks for the report, Kominop.

Since nothing appears under Settings > About Firefox > Crashes, it’s possible that Android is killing Firefox, for example to free up memory. Firefox has a debug screen that shows the reasons Android reported for stopping its processes, which could help us investigate.

The next time Firefox closes on its own, could you please follow these steps just after reopening it?

1. Go to Settings > About Firefox and tap the Firefox logo five times to reveal Secret Settings.
2. Open Secret Settings, scroll to the Debug section, and turn on Enable Debug Drawer.
3. Return to the browser and tap the floating Open debug drawer button.
4. Open Tab Process Exits.
5. Take a screenshot of the entries from around the time Firefox closed and attach it here. The most recent entries are at the top.

These entries show the reason Android reported for stopping each process, along with information about its memory usage. Please check the screenshot for anything you don’t want to share before attaching it, as this report is public.

It would also help to know:

• Roughly how many tabs were open when this happened?
• Did your device show any low-storage or low-memory warnings around that time?

If you already have adb set up on a computer, you can optionally share the output of this command for additional detail:

adb shell dumpsys activity exit-info org.mozilla.firefox

Please remove anything you don’t want to share before posting the output.

You can turn Enable Debug Drawer off again afterwards in Secret Settings (which itself will automatically be turned off on the next fresh app launch).

Thanks

Comment 3

[kominops]

Attachment: Screenshot_20261014-140127_Firefox_Beta.webp

Comment 4

[kominops]

Attachment: Screenshot_20261014-140134_Firefox_Beta.webp

Comment 5

[kominops]

4 tabs where open
No warning (200GB free storage space, no other applications where open so RAM should be sufficient)
Attached images Screenshot_20261014-140127_Firefox_Beta.webp and Screenshot_20261014-140134_Firefox_Beta.webp

Comment 6

[twhite]

Thank you so much Kominops! Appreciate the screenshots here, this is really helpful for the investigation into the bug.