Open Bug 1732196 Opened 3 years ago Updated 4 months ago

Pinch to zoom lag in fenix on gsmarena's desktop site


(Core :: Graphics: WebRender, defect)




Performance Impact low


(Reporter: mcomella, Unassigned)


(Depends on 1 open bug, Blocks 2 open bugs)


(Keywords: perf:responsiveness)

From github:

Steps to reproduce

  1. Go to
  2. Switch to desktop view
    3.Try zoom in and zoom out (either pinch to zoom or double tap hold and swipe to zoom)

Expected behaviour

Smooth pinch to zoom animation

Actual behaviour

Laggy animation and sometimes doesn't zoom out

Device name

Samsung Galaxy M51

Android version

Android 11

Firefox release type

Firefox Nightly

Firefox version


Device logs

No response

Additional information

Change performed by the Move to Bugzilla add-on.

Summary: [Bug]: pinch to zoom lag → Pinch to zoom lag in fenix on gsmarena's desktop site

I was able to reproduce on my Moto G5 (it is sometimes subtle) and took a profile:

I'm gonna guess graphics for a first pass.

Component: Panning and Zooming → Graphics: WebRender

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit auto_nag documentation.

Flags: needinfo?(jmathies)
Blocks: wr-perf
Severity: -- → S4
Flags: needinfo?(jmathies) → needinfo?(jnicol)

I can't really reproduce on Sony 10 II, or at least I can't see difference to Chrome. But based on the profile (comment 1) there are some slow composites

Whiteboard: [qf] → [qf:p3:responsiveness]
Blocks: wr-android-perf
No longer blocks: wr-perf
Performance Impact: --- → P3
Whiteboard: [qf:p3:responsiveness]

I can reproduce stuttering whilst zooming out, but not whilst zooming in. I think this is therefore related to the "low-quality pinch-zoom" mode, which is only enabled on nightly. Disabling that improves things for me.

Depends on: 1761157
Flags: needinfo?(jnicol)
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