react-native-system-uptime

Get system uptime (time since last device boot/restart) from React Native.

This library is implemented as a TurboModule and exposes synchronous methods to read uptime in milliseconds and microseconds.

Features

• Works on iOS and Android
• Synchronous reads (no bridge round-trips)
• Returns uptime in ms and µs

Requirements

• React Native New Architecture enabled (RCT_NEW_ARCH_ENABLED=1 / newArchEnabled=true)
• iOS: CocoaPods

If you are not using the New Architecture, this package will not load because it uses TurboModuleRegistry.getEnforcing.

Installation

React Native CLI

yarn add react-native-system-uptime

iOS:

cd ios && pod install

Expo

This is a native module. Use it with a custom dev client or a prebuilt app:

npx expo prebuild

Usage

Basic

import { getUptimeMs, getUptimeUs } from 'react-native-system-uptime';

const uptimeMs = getUptimeMs();
const uptimeUs = getUptimeUs();

console.log({ uptimeMs, uptimeUs });

React component

import * as React from 'react';
import { Text } from 'react-native';
import { getUptimeMs } from 'react-native-system-uptime';

export function UptimeLabel() {

  const [uptimeMs, setUptimeMs] = React.useState(() => getUptimeMs());

  React.useEffect(() => {
    const id = setInterval(() => setUptimeMs(getUptimeMs()), 1000);
    return () => clearInterval(id);
  }, []);

  const uptimeSeconds = Math.floor(uptimeMs / 1000);
  return <Text>Uptime: {uptimeSeconds}s</Text>;
}

API

All methods are synchronous and return a number.

getUptimeMs(): number

Returns milliseconds since the device booted.

getUptimeUs(): number

Returns microseconds since the device booted.

Error behavior

If the native call fails, the module returns -1.

Implementation notes

• Android: uses SystemClock.elapsedRealtime()
• iOS: computed from KERN_BOOTTIME (via sysctl) and the current time

Troubleshooting

“TurboModuleRegistry.getEnforcing(...): 'SystemUptime' could not be found”

• Ensure New Architecture is enabled.
• Rebuild the app after installing the package.
• iOS: run pod install.

Development

• Run the example app: yarn example
• Typecheck: yarn typecheck
• Tests: yarn test

Contributing

• Development workflow
• Sending a pull request
• Code of conduct

License

MIT

Built with create-react-native-library