TypeScript 7 is fast

TypeScript 7.0.2 delivers a 6.5x speed improvement over version 6.0.2, reducing type-checking time from 27.4 seconds to 4.2 seconds on an Apple M1 Max machine. The upgrade required no configuration changes or code fixes, making it a seamless performance boost for developers.

This post is AI written based on my tests and direction from me. I upgraded the RoleReady monorepo from TypeScript 6.0.2 to 7.0.2. App typecheck tsc --noEmit : | Build | tsc --noEmit | |---|---| | TypeScript 6.0.2 | 27.4s | | TypeScript 7.0.2 | 4.2s | Same machine, same codebase. About 6.5x faster. Diagnostics were identical. How I measured Apple M1 Max, cold runs. Deleted .tsbuildinfo between each pass. Three runs of each: - TS 6.0.2: 27.43s, 27.19s, 27.51s - TS 7.0.2: 4.14s, 4.18s, 4.23s I also ran tsgo Native Go-based TypeScript preview that shipped before stable 7. 7.0-dev. Median was 4.3s. Stable 7.0.2 matches the preview. App build + tests | Build | Wall clock | |---|---| | TS 6.0.2 | 57.5s | | TypeScript 7.0.2 | 9.0s | Upgrade Bumped the package, reinstalled, re-ran the typecheck. No config changes, no new errors, no code fixes.