Thumb flickers and jumps when slider value is set programmatically

[abrahamgalue]

Environment

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• are you using the new architecture? Yes

• which version of react & react-native are you using? 18.3.1

Description

I'm using Expo 52 and using a simple Slider that follows the official documentation, and the slider thumb just jumps and causes weird UI behavior. I'm using an Expo Development Build and testing it on an Android device. Here's the simple example:

Reproducible Demo

export const LightLevel = () => {
	const [value, setValue] = useState(10)
	return (
		<>
			<Text>Light: {value && +value.toFixed(3)}%</Text>
			<Slider
				style={{ width: 200 }}
				step={1}
				minimumValue={0}
				maximumValue={100}
				value={value}
				onValueChange={setValue}
				minimumTrackTintColor={'#00629A'}
				maximumTrackTintColor={'#979EA4'}
			/>
		</>
	)
}

[panna-oo]

@abrahamgalue
debounce((val) => {
setValue(val);
}, 50);

[abrahamgalue]

This only delays the bug, but does not solve the problem.

[IlyaPasternakAmitech]

I'm facing the same issue with the thumb flickering and jumping when setting the value programmatically.

As a temporary workaround, I’ve implemented a check using isSliderTouched to ensure that setValue is only triggered during user interaction (onTouchStart / onTouchEnd). This seems to prevent the flickering/jumping behavior for now:

export const LightLevel = () => {
  const [value, setValue] = useState(10);
  const [isSliderTouched, setIsSliderTouched] = useState(false);

  return (
    <>
      <Text>Light: {value && +value.toFixed(3)}%</Text>
      <Slider
        style={{ width: 200 }}
        step={1}
        minimumValue={0}
        maximumValue={100}
        value={value}
        onValueChange={(value) => {
          if (!isSliderTouched) {
            return;
          }
          setValue(value);
        }}
        minimumTrackTintColor={'#00629A'}
        maximumTrackTintColor={'#979EA4'}
        onTouchStart={() => setIsSliderTouched(true)}
        onTouchEnd={() => setIsSliderTouched(false)}
      />
    </>
  );
};

While this doesn't fix the root cause, it at least stops the slider from jumping when the value is updated externally.

[abrahamgalue]

For now, in my app, I'm using a similar approach. For my status, I use Zustand since there are several parameters that are going to be changed, but here's an example.

import { View } from 'react-native'
import { useDevicesActions } from '@/store/devicesStore'
import { Text } from '@/components/ui/text'
import Slider from '@react-native-community/slider'

function LightLevel({ deviceId, brightness }) {
	const { handleDeviceBrightness } = useDevicesActions()

	return (
	  <View>
		<Text className='px-8 text-start text-modal-secondary'>
			LIGHT {brightness}%
		</Text>
		<Slider
			style={{ width: 240 }}
			step={1}
			lowerLimit={0}
			upperLimit={100}
			minimumValue={0}
			maximumValue={100}
			value={brightness}
			onSlidingComplete={(value) => handleDeviceBrightness(deviceId, value)}
			thumbTintColor={'#D9D9D9'}
			minimumTrackTintColor={'#D9D9D9'}
			maximumTrackTintColor={'#538297'}
		/>
	</View>
	)
}

The only issues I've encountered are that the brightness value doesn't update in real time, and in the React inspector with the React Developer Tools, the slider seems to re-render many times when you move it to change its value. This is unlike when using a similar approach to the one in the documentation, which seems more optimized, but causes these flickering and jumps.

For now, I'll leave it with this approach until I get more information or an official solution.

[draggie]

Hi, thanks for reporting.
I have tried reproducing that on both provided setup and our example which runs on React 19.0 and React Native 79 but without much success.
Could you maybe record video or give some more context ?
For me setting value programatically works fine, I do not see any flickering, at least not on the emulator.

[meleffendi]

I'm having the same issue on Android emulator. I'm using React 19.0.0 and RN 0.79.5. The flickering happens when I press the slider, move it and release while still moving. If I release while stopped, it does not happen.

Screen.Recording.2025-07-20.113714.mp4

Here is a video:

[abrahamgalue]

Hi, thanks for reporting. I have tried reproducing that on both provided setup and our example which runs on React 19.0 and React Native 79 but without much success. Could you maybe record video or give some more context ? For me setting value programatically works fine, I do not see any flickering, at least not on the emulator.

@draggie Of course, as I said before I am using an Expo build for development and I run the project with the bunx expo start command on a physical device with Android 15, using React 18.3.1 and react-native 0.76.9, with Expo 52, because in Expo 53 there is a problem with the Supabase library that I use for authentication so I hope they fix it to update.

Here you have a little video to see the behavior I am getting:

Screenrecorder-2025-07-20-13-44-20-924.mp4