Startup performance

Native initialization, JavaScript bundle loading, React rendering, and first-screen data all affect startup time. This package can optimize the splash retention and exit path; it is not a replacement for full startup profiling.

Priorities

1. Hide at the right time

Avoid a fixed setTimeout. Call hide() immediately after navigation, fonts, and essential first-screen data are ready. This removes unnecessary waiting without exposing an empty root view.

2. Use Android system mode

For a centered logo on a solid background:

{
  "android": {
    "mode": "system",
    "image": "./assets/splash-logo.png",
    "backgroundColor": "#F1F5F1"
  }
}

This skips full-screen layout inflation and Dialog creation. The tradeoff is no Android custom transition, full-screen artwork, or post-startup show().

3. Shorten the exit

Animated transitions default to 250 ms. Startup-sensitive apps can use a 180-220 ms fade or none. Animation time is included in hideDuration.

4. Optimize artwork

• Avoid decoding images far larger than the target screen.
• Prefer a focused logo asset with intentional transparent padding.
• Crop full-screen artwork for each platform instead of fixing composition at runtime.
• Use NinePatch for stretchable Android backgrounds and define its stretch regions correctly.

Startup metrics

const metrics = await SplashScreen.getStartupMetrics();
console.log(metrics);

Field	Meaning
showTime	Native splash retention started
hideRequestedTime	Native code received hide()
hiddenTime	The splash was actually removed
nativeVisibleDuration	showTime to hiddenTime
hideDuration	hideRequestedTime to hiddenTime, including animation

Phases that have not occurred return null. Timestamps come from a monotonic platform clock and are only comparable inside the current app process.

Measurement boundary

getStartupMetrics() does not measure total cold start, JavaScript bundle loading, React's first render, or time to interactive. Compare Release builds with cold starts on the same device and first-screen data conditions, and collect multiple runs.