TypeScript 7.0 went GA on July 8 — and it is one of those rare releases where the headline is a single word: fast. Microsoft ported the compiler to Go under the codename Project Corsa. The key word is port, not rewrite: the structure and logic of the original TypeScript codebase were carried over as faithfully as possible so the results stay consistent. The payoff is a compiler that runs 8 to 12 times faster than its predecessor.
What the benchmark shows
The most-cited measurement is the VS Code codebase — 1.5 million lines of TypeScript. TypeScript 6 took 125.7 seconds. TypeScript 7 does the same job in 10.6. The new compiler is also multi-threaded: the experimental --checkers flag controls how many workers type-check in parallel. With eight workers the VS Code check falls to 7.5 seconds. Editor startup drops from 9.6s to 1.2s; memory usage roughly halves. For large codebases this is the difference between a coffee-machine break and instant feedback.
Good news with an asterisk
TypeScript 7.0 ships without a stable programmatic API — expected in TypeScript 7.1, pencilled in for around October 2026. That creates a real gap: Vue, Svelte, Astro, MDX and Angular template type-checking cannot simply flip the switch. Vue and Svelte projects should stay on TypeScript 6 for now. Angular teams can run TypeScript 7's tsc for CLI checks and gain the speed there, but still need TypeScript 6 for editor support. Microsoft ships a @typescript/typescript6 compatibility package to run both side-by-side while you wait.
Our take
A compiler that runs ten times faster is normally the kind of promise that does not land. This one did. Project Corsa is not an experiment — it is a faithfully ported compiler that behaves like the existing one but performs at a completely different speed tier. If your project runs on Next.js or React without framework-specific template transforms, upgrading now is the obvious call. On Vue or Svelte? Hold for 7.1 — a few months out, but a compiler this much faster is absolutely worth the wait.
