Jitter/flickering when scrolling upwards through variable-height items after prepending data

[jessejanderson]

Description

When items are prepended to a FlashList with variable-height content, scrolling upwards through the newly added items causes visible jitter/flickering. The content visibly jumps as items are measured during scroll.

Current behavior

• Fixed-height items: No jitter
• Variable-height items: Jitter present
• FlatList does NOT exhibit this issue on iOS

FlashList (jitter)

ScreenRecording_01-03-2026.17-52-06_1.mp4

FlatList (no jitter)

ScreenRecording_01-03-2026.17-51-39_1.mp4

Expected behavior

Smooth scrolling without significant jitter when scrolling upwards through prepended variable-height items.

Reproduction

Expo Snack or minimal reproduction link:

https://snack.expo.dev/@jessejanderson/flash-list-jitter

Platform

• iOS
• Android
• Web (if applicable)

Environment

FlashList version: 2.2.0
React Native version: 0.81 (Expo SDK 54)

Additional context

In the app where I first ran into this issue, I've tried a number of recommendations from the v2 documentation and other sources, but none of them have resolved the issue.

• Memoized props
• Proper keyExtractor usage to return unique, stable keys for each item.
• Using getItemType to better predict height for different item types.
• Tested various drawDistance values. Nothing but extremely high values (10000+) made a significant difference.
• Deferred state updates during scroll.
• scrollEventThrottle={16}
• Confirmed no key props
• A bunch of random other things. 🙃

None of these resolved the issue (other than the extremely high drawDistance values, which eventually break when the prepended/new item count is high enough).

Checklist

• I've searched existing issues and couldn't find a duplicate
  (there are some similar issues, but involve multi-column layouts or other more complex setups)
• I've provided a minimal reproduction (Expo Snack preferred)
• I'm using the latest version of @shopify/flash-list
• I've included all required information above

[07abhishekrock]

In your example code, instead of firing setTimeout every n milliseconds, you can wait for the previous scroll to complete before initiating a new one ? Does that fix the issue ?

[Samykills]

same,
using rn - 0.83
and "@shopify/flash-list": "2.1.0",

Update - my issue was that i had Animations on the renderedITEMS - entering and layout

entering={FadeInDown.delay(ANIMATION_TIME.MS_200)}
     layout={LinearTransition.springify().duration(ANIMATION_TIME.MS_250)}

and that was causing a flicker as it was conflicting with the recycle mechanism, i have removed these animations for now from the items and its resolved, also check this if it helps - https://shopify.github.io/flash-list/docs/1.x/guides/reanimated#layout-animations