TypeScript compiler ported to Rust
Archived — this story has rotated out of today’s deck. It is kept here in full.
The gist
Cloudflare and VoidZero are taking ownership of tsrs, a Rust port of the TypeScript compiler.
The port claims up to 8x speed and 70% less memory, pending independent checks.
Background
TypeScript is Microsoft's programming language that builds on JavaScript by adding type checking, and its compiler turns that code into runnable JavaScript. Microsoft shipped TypeScript 7.0 in July 2026, replacing its JavaScript-based compiler with one written in Go for roughly tenfold speed gains; Microsoft had considered Rust but concluded reproducing TypeScript's architecture in Rust would bring complications around memory management and compatibility. Developer and YouTuber Theo Browne then used AI agents to port the compiler to Rust, and Cloudflare and VoidZero followed by incubating tsrs inside the Oxc JavaScript compiler toolchain, in close collaboration with the TypeScript team. Rust's memory model is cited as an advantage for running in WebAssembly, where Go requires compiling its garbage collector along with the program.
How it unfolded
- Jul 2026Microsoft released TypeScript 7.0, replacing its JavaScript-based compiler with one written in Go and delivering roughly tenfold speed improvements.
- Oct 15, 2026Developer and YouTuber Theo Browne's AI-agent port of the TypeScript compiler to Rust (TS_Rust) was reported; he claims it runs twice as fast as Microsoft's Go-based TypeScript 7 and 12.5 times as fast as TypeScript v6.
- Oct 20, 2026Cloudflare and VoidZero announced they are working with Max Schwenk of Owner.com on tsrs, a Rust port of the TypeScript compiler incubated as part of the Oxc JavaScript compiler toolchain in close collaboration with the TypeScript team.
- Oct 20, 2026Cloudflare director of engineering Christoph Nakazawa confirmed on X that the company is taking ownership of tsrs, claiming it is up to eight times faster and uses 70% less memory than TypeScript 7.0.
- Oct 21, 2026The Diff newsletter listed tsrs among its items, citing benchmarks of up to 8x faster and ~70% less memory, with 358 points on Hacker News.
- Oct 21, 2026Theo Browne's podcast summary said the Rust rewrite was working in under 20 hours, runs two to three times faster than TSGO, works in WASM, and hits 99.99% accuracy against other TypeScript versions on real projects.
Who’s saying what
- Support
- Theo Browne said the Rust rewrite was working in under 20 hours and called it astonishing that it not only passes tests but works as a TypeScript replacement.
- Official
- Christoph Nakazawa of Cloudflare said the company is not forking TypeScript but working with the TypeScript team, and that 7.1 is already about 2.5x faster as a result.
- Caution
- Max Schwenk of Owner.com said a faster compiler that finds fewer errors is a broken compiler with good marketing.
- Analysts
- BigGo Finance noted Browne's speed figures come from his own testing and require independent verification.
Still unverified
Theo Browne claims his Rust port runs twice as fast as Microsoft's Go-based TypeScript 7 and 12.5 times as fast as TypeScript v6, though he says he has not inspected the code; BigGo Finance reports the figures come from his own testing and require independent verification.