Instant Performance Upgrade: From FlatList to FlashList
Article Summary
Shopify's React Native team just solved one of mobile development's most persistent headaches: getting lists to scroll smoothly without blank cells or frame drops.
The React Native Foundations team built FlashList, an open-source drop-in replacement for FlatList that delivers native-like performance across all devices. After seeing consistent performance issues with FlatList on lower-end Android devices, they created a solution that works seamlessly on everything from budget phones to flagship devices.
Key Takeaways
- FlashList delivers 7.5x better JavaScript FPS compared to FlatList on low-end devices
- Recycles existing views instead of creating new ones, drastically reducing memory footprint
- Nearly identical API to FlatList makes migration take seconds, not days
- Moves layout operations to native layer, eliminating UI glitches from incorrect size estimates
- Already deployed across Shopify Mobile, Shop app, and POS with measurable improvements
Critical Insight
FlashList maintains 60+ FPS even on budget Android devices while using a fraction of the memory, with almost zero migration effort required.
