# Rendering is slow & flickers on firefox

**URL:** <https://discourse.threejs.org/t/rendering-is-slow-flickers-on-firefox/85192>\
**Category:** Questions\
**Tags:** firefox\
**Created:** [July 15, 2025, 12:11pm UTC](https://discourse.threejs.org/t/rendering-is-slow-flickers-on-firefox/85192 "2025-07-15T12:11:28Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Bux42](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.threejs.org/bux42/32/61653_2.png) [@Bux42](https://discourse.threejs.org/u/Bux42)\
**Post date:** [July 15, 2025, 12:11pm UTC](https://discourse.threejs.org/t/rendering-is-slow-flickers-on-firefox/85192/1 "2025-07-15T12:11:28Z")

</div>

Hello all

I’m trying to find and fix the root cause of some lags that only **happens in firefox**

Reproduction steps:  
Go to [https://tmdojo.com/maps/j3FTAEgaMI5LdO3vzfBcX1feBE3](https://tmdojo.com/maps/j3FTAEgaMI5LdO3vzfBcX1feBE3)  
Load the first replay (doesn’t matter which one)

 ![image](https://canada1.discourse-cdn.com/flex035/uploads/threejs/original/3X/5/4/54f04ebf41e53cd55b9c2b6aa7f025e5a793c95b.png)

Close the “Select replays” panel

 ![image](https://canada1.discourse-cdn.com/flex035/uploads/threejs/original/3X/0/2/021279a75c86bcfe61725dbb9019ee13ed496c8e.png)

Click the eye icon to set the cam to “follow” mode on the loaded replay

 ![image](https://canada1.discourse-cdn.com/flex035/uploads/threejs/original/3X/0/f/0faeaf1087b15e74f73c6ce449c351c40d822374.png)

Click the “Play” button on the footer

 ![image](https://canada1.discourse-cdn.com/flex035/uploads/threejs/original/3X/4/3/43c6d83f9766468523af24eaef2f4d155ee698bc.png)

On chrome, it’s going smoothly at 144 FPS, no flickering  
On FireFox, it’s going at 0.3 x speed, with some flickering

I tried looking at the profiler on both chrome and firefox to try and spot the differences, but they look nothing alike

The code that introduces the lag can be found [here](https://github.com/Bux42/TMDojo/blob/5a2b90f07de0c1215a40f0fafef21ce118de9eda/app/components/viewer/ReplayCars.tsx)

Any idea on what could be the issue?

Regards

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<div class="post-metadata">

**Author:** ![grml](https://avatars.discourse-cdn.com/v4/letter/g/e36b37/32.png) [@grml](https://discourse.threejs.org/u/grml)\
**Post date:** [July 15, 2025, 12:25pm UTC](https://discourse.threejs.org/t/rendering-is-slow-flickers-on-firefox/85192/2 "2025-07-15T12:25:00Z")

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FWIW, it runs at full speed for me, no flickering in Firefox/Linux on a crappy Intel GPU.

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<div class="post-metadata">

**Author:** ![Bux42](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.threejs.org/bux42/32/61653_2.png) [@Bux42](https://discourse.threejs.org/u/Bux42)\
**Post date:** [July 15, 2025, 12:36pm UTC](https://discourse.threejs.org/t/rendering-is-slow-flickers-on-firefox/85192/3 "2025-07-15T12:36:52Z")

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Interesting  
I’m on windows with a NVIDIA GPU

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<div class="post-metadata">

**Author:** ![vis\_prime](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.threejs.org/vis_prime/32/39829_2.png) [@vis\_prime](https://discourse.threejs.org/u/vis_prime)\
**Post date:** [July 15, 2025, 1:56pm UTC](https://discourse.threejs.org/t/rendering-is-slow-flickers-on-firefox/85192/4 "2025-07-15T13:56:51Z")

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yeah i can replicate, I’m on nvidia too

chrome left , firefox right

Camera movement is smooth, but the vehicle movement is stuttering.

Looks like some sort of precision issue , are you using `performance.now()` or `date.now()` ?

also try using `Timer` from three/addons instead of THREE.clock