React Native: Android Cuts JNI Cost, Hermes Trims Regex Bloat
Android touch handling and Turbo Module calls got measurably cheaper by cutting repeated JNI work, while Hermes V1 stopped expanding unicode regexes to save size and memory. A cluster of UI correctness fixes rounds out the day.
Duration: PT2M30S
Episode overview
This episode is a short developer briefing from React Native.
It explains recent repository work in plain language.
- Show: React Native
- Published: 2026-10-29T13:03:58Z
- Audio duration: PT2M30S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good morning, it's Thursday, October 29th, 2026.
The lead signal is Android doing less bridging work per frame — with measured CPU and memory wins on touch handling and Turbo Module calls.
First theme is cheaper Java-to-native handoffs. PR 59554 rebuilds Android touch event payloads in native code, dropping from around 20 to 25 J-N-I calls per move event to two. Testing cited an 8.7 percent drop in main-thread CPU during sustained drags, 31 percent faster touch-move handling, and about 10 megabytes…
Second, smaller bundles for Hermes version one. Merged PR 59580 stops lowering U-flag regular expressions in the Babel preset, since Hermes compiles them natively. The report cites roughly 64 kilobytes less bytecode in a test app, almost 600 kilobytes less live heap on regex-heavy libraries, and up to 17 percent…
Third, user-visible correctness fixes. PR 59383 fixes text inside a modal not updating after a live font-scale change. PR 57959 fixes maintain visible content position anchoring to the wrong child when z-index reorders views. PR 59559 treats zero-height keyboard shows on foldable iPhones as hide events, and PR 59524…
What's next: validate the Android performance work on low-end…
Nearby episodes from React Native
- Weekly Recap - Bridge Cleanup and Layout Performance
- Hermes Crash Reporting Fix and Rendering Reproducers
- Bridge Teardown, Layout Speedups, Cheaper E2E
- Android Bridge Efficiency and Style Fixes
- Props 2.0 Payload Fixes and Lost Tap Repair
- Touch Reliability, Text Fixes, and Startup Cleanup
- Android Activity Leaks and iOS Scroll Parity
- Weekly Recap - Legacy Bridge Cleanup and Accessibility Fixes