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[Android] Extreme lag after upgrade to 0.39.2 and 0.40.0

Freshalmost 9 years ago
Mar 14, 20260 views
Confidence Score82%
82%

Problem

Description Updating from 0.36.0 to 0.39.2 and 0.40.0 renders the app unusable after minimal interaction. The javascript thread slowly grinds to a halt until it becomes unresponsive. Native UI, such as scrolling or native animations is unaffected. Problem persists with 0.41.0-rc.0 It works perfectly well with 0.38.0 Reproduction I managed to reproduce this in a freshly installed app with an infinite scroll list containing rows with images. With 0.40.0, the JS driven animation begins to lag after only ~150 items. WIth 0.38.0, animation stays smooth as long as there is no rendering. See attached videos below: 0.38.0 0.40.0 Test app can be found here A relative StackOverflow question. Solution I suspect the new C-based CSS implementation, as that is the only major change from 0.38 to 0.39. Another reason could be a problem with removeClippedSubviews. Additional Information React Native version: 0.39.2 / 0.40.0 Platform: Android * Operating System: MacOS

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1 Fix

Canonical Fix
High Confidence Fix
77% confidence100% success rate5 verificationsLast verified Mar 14, 2026

Solution: [Android] Extreme lag after upgrade to 0.39.2 and 0.40.0

Low Risk

I want to add my voice to this chorus. I upgraded from 0.34.1 to 0.40. I was pleasantly surprised by some of the improvements (Dailymotion working well within the Webview, some keyboard problems fixed, screen rotation with better behavior) but then I realised the performance drop. I was close to releasing my app but the problem is so bad I have to wait. Still waiting. Coded as a stop-gap a simple

77

Trust Score

5 verifications

100% success
  1. 1

    I want to add my voice to this chorus. I upgraded from 0.34.1 to 0.40. I was ple

    This is an extremely serious, almost fatal issue for many projects. I hope it gets fixed very soon.

Validation

Resolved in facebook/react-native GitHub issue #11809. Community reactions: 9 upvotes.

Verification Summary

Worked: 5
Partial: 1
Last verified Mar 14, 2026

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Environment

Submitted by

AC

Alex Chen

2450 rep

Tags

react-nativemobileiosandroidresolution:-locked