Cloudflare announced on 20 October 2026 a Rust rewrite of the TypeScript compiler, called tsrs. VoidZero and Max Schwenk of Owner.com help build it, and it is being incubated within the Oxc toolchain. Cloudflare says it works with the TypeScript team and is not forking the language. With the same number of type check workers, it reports tsrs up to 8x faster than TypeScript 7.0, using about 70% less memory. It adds that TypeScript 7.1 beta is up to 2.5x faster than 7.0, partly from tsrs changes. An experimental release is on npm.
TypeScript 7.0 is the team's own Go port of the compiler, so tsrs redoes that work in Rust. Cloudflare says Rust suits WebAssembly better: Go code compiled to it must carry Go's garbage collector, while Rust shares memory with its host simply. It says lower memory use helps run toolchains in Workers, browsers and sandboxes. Still open: tsrs differs from upstream today, for example in the order of diagnostics (error messages). Cloudflare aims to narrow this before a stable release but gave no date. The benchmarks are Cloudflare's own. It is also working with Theo Browne to merge tsc-rs and tsrs, with no timeline.
The contest to speed up TypeScript is now partly about where the compiler can run, not only how fast. A port must also follow upstream decisions, or Cloudflare says it falls apart. Ask your engineers how much CI and editor time goes to type checking, and whether anyone outside Cloudflare has reproduced these numbers.