Huge performance loss in new arch when using animated components

[WadhahEssam]

Description

We have been ready for new arch since day 1, and the only thing that stopped us from migrating is having the performance issues with reanimated, and until today (expo 54, reanimated 4.1.0, rn 81.4) sadly it wasn't solved.

The issue is very simple.

Scrolling in a screen with many animated views will always cause huge UI drops (depending on the amount of reanimated views you have)

We enabled all RN and Reanimated feature flags and still its the same.

Here is a comparison between old arch and new arch using the same code. and same version, (had to switch reanimated to 3.19)

Example running 300 reanimated views

Old Arch:

Screen.Recording.2025-09-17.at.8.39.55.PM.mov

New Arch:

new-arch.mov

Here is the repo for the same code (its pretty simple and straight forward)
https://github.com/WadhahEssam/expo54reaniamted

old arch in in old-arch branch inside the same repo

All what we would like to know is if that is something the sm team is aware of and having a plan to fix. or we can have to live with it and find other solutions to mitigate it for the time being?

Thank you SM for your amazing work and help for the community.

Steps to reproduce

Here is the repo for the same code (its pretty simple and straight forward)
https://github.com/WadhahEssam/expo54reaniamted

old arch in in old-arch branch inside the same repo

Snack or a link to a repository

https://github.com/WadhahEssam/expo54reaniamted

Reanimated version

4.1.0

Worklets version

0.5.0

React Native version

0.81.4

Platforms

iOS

JavaScript runtime

Hermes

Workflow

Expo Dev Client

Architecture

None

Build type

Debug app & dev bundle

Device

No response

Host machine

None

Device model

IPhone 16

Acknowledgements

Yes

[WadhahEssam]

Upon more experiments, I have got an even more serious issue with new arch.

using this branch (https://github.com/WadhahEssam/expo54reaniamted/tree/new-arch-animated-view-with-no-animations)

if you have animated component, (even if its not animating) the JS thread drops to almost 0 when scrolling.

Screen.Recording.2025-09-18.at.11.19.50.AM.mov

So when your component is animating you get half frame rates and 60 JS frames.
but when its not, you get 55-58 UI framees and 2-10 JS Frames.

And the interesting thing here, is that scrolling should have nothing to do with JS Frames. nothing in the code is actually using any scrolling related code.

[WadhahEssam]

@expodeveloper2026 Although you have got a disrespectful tune but I will answer you.

• no matter if its 300 or 3000 views. if the performance is halved between old and new arch, then this is a fact.
• our app is huge and uses very complex animations which resulted in the differences be more obvious with less views.
• the issue happens even if nothing is animating, scrolling the screen causes the issue, which indicates an internal issue somewhere.

[deepanshuisky]

Facing similar issues , Not sure if I can check and refactor all individual component .
This is second time i am trying new arch previously with 3.17 (react-native 0.79.5) all of my app went jittery.
This time i upgraded to 4.0.1 (react-native 0.79.6) jitter is still there on some screen , and after some usage it become worse

[expodeveloper2026]

Facing similar issues , Not sure if I can check and refactor all individual component . This is second time i am trying new arch previously with 3.17 (react-native 0.79.5) all of my app went jittery. This time i upgraded to 4.0.1 (react-native 0.79.6) jitter is still there on some screen , and after some usage it become worse

Which setup are you on, Expo or bare RN ?

[deepanshuisky]

Facing similar issues , Not sure if I can check and refactor all individual component . This is second time i am trying new arch previously with 3.17 (react-native 0.79.5) all of my app went jittery. This time i upgraded to 4.0.1 (react-native 0.79.6) jitter is still there on some screen , and after some usage it become worse

Which setup are you on, Expo or bare RN ?

Bare RN

[ahmeddesigner23]

Thanks for detailing this so well @WadhahEssam really appreciate you opening this and sharing the repo. We’ve been stuck on Expo 52 for the exact same reason. Tried moving to Expo 53 back in May 2025 and ran into the same performance drops. Hoping the Reanimated team can get this sorted out soon

[pavelbabenko]

Same issue with Expo 54

[ahmeddesigner23]

Interesting that it's still happening on 54. What was your experience with Expo 53, @pavelbabenko? Especially curious if scroll-based animations were smoother there.

[RohovDmytro]

It's been like this for months. I would say it's a big blocker. After hours of investigation I don't have anything practical to read.

[expodeveloper2026]

It's been like this for months. I would say it's a big blocker. After hours of investigation I don't have anything practical to read.

Animations in general stay fluid, only the scroll related ones sometimes stutter

[RohovDmytro]

@expodeveloper2026 cool.

The "only" thing is my app is 95% lists with animations. Also, Google Play does not enjoy stuttering.

[expodeveloper2026]

@RohovDmytro

Just asking if your scroll animations include interpolate and did you notice same lag in iOS

[mzaien]

@tomekzaw I hope this repro is easy to debug and find a fix for this issue 🙏