Measuring Render Performance with Jetpack Compose

Premise's Android team put Jetpack Compose 1.0 through rigorous performance testing before adopting it in production. The results? Surprising insights about render times, cold starts, and optimization strategies.

Will Shelor and the Premise engineering team measured Compose performance across multiple devices and configurations, comparing pure Compose, XML hybrid approaches, and traditional XML layouts. They tested everything from flagship phones to budget devices without Google Play Services.

Key Takeaways

• Compose rendered 33% slower than XML initially, but only 10% with AOT profiles
• R8 and debuggability settings cut render time by over 1 second on slow devices
• First Compose launch took twice as long as subsequent renders due to initialization
• Pre-loading Compose on a splash screen reduced main screen launch time by 400ms
• ComposeView in RecyclerViews was slowest; setContent and base ComposeView performed equally

The team discovered a clever workaround to eliminate Compose's initialization penalty, and Google's Leland Richardson explained why production apps perform even better than their tests showed.