Show HN: Warper – The fastest React virtualization library, built with Rust/WASM

I built the fastest React virtualisation library. The core is written in Rust and compiled to WebAssembly.

10 million rows at 120+ FPS. No lag. No dropped frames.

Existing libraries like react-window and react-virtuoso hit walls at scale. They rely on JavaScript binary search and O(n) scans for variable heights. Warper is different.

The engine uses:

- Fenwick trees for O(log n) variable-height lookups - O(1) arithmetic for fixed-height items - Zero-copy typed arrays between WASM and JS - Pre-allocated memory pools with zero GC during scroll

Benchmarks on M1 MacBook Pro with 1M rows: Warper hits 119 FPS. react-virtuoso drops to 58 FPS. At 10M rows Warper stays at 118 FPS while virtuoso falls to 31 FPS.

Its not marginally faster. Its 2-4x faster depending on the workload.

Trade-off is bundle size: around 45KB vs 6KB for react-window. Worth it if you need the performance.

Available through GitHub Sponsors at github.com/sponsors/itsmeadarsh2008

Happy to answer questions about the architecture.