TypeScript 7.0 has arrived, shifting the compiler to a native Go-based port for an order-of-magnitude leap in performance.

TL;DR Link to heading

  • 10x Speed: Up to 12x faster full builds and 13x faster editor diagnostics.
  • Leaner Memory: Uses up to 26% less aggregate memory on large projects.
  • Native Parallelism: New --checkers and --builders flags for multi-core scaling.
  • Stable Watching: Rebuilt --watch mode powered by a native port of Parcel’s watcher.
  • Strict Defaults: Adopts modern standards like strict: true and module: esnext.

Unprecedented Performance Link to heading

By faithfully porting the codebase to Go, TypeScript 7.0 leverages native speed and shared-memory multithreading. The VS Code codebase now builds in 10.6 seconds (down from 125s), and first-error diagnostics appear in just 1.3 seconds. Major teams like Slack and Vanta report CI time reductions of 40% to 90%.

Scaling and Infrastructure Link to heading

New experimental flags allow developers to fine-tune performance:

  • --checkers: Parallelizes type-checking (default is 4 workers).
  • --builders: Parallelizes project reference builds in monorepos.
  • --watch: Replaces the expensive polling of old with a high-performance Go port of the Parcel file-watcher.

Modernizing the Language Link to heading

This release enforces modern configurations and removes legacy debt:

  • New Defaults: strict, stableTypeOrdering, and noUncheckedSideEffectImports are now true by default.
  • Hard Errors: Support for target: es5, baseUrl, and moduleResolution: node has been removed in favor of modern equivalents like nodenext and bundler.
  • Unicode Support: Template literal types now correctly treat emojis as single units instead of UTF-16 surrogate pairs.

Compatibility & Setup Link to heading

Because TypeScript 7.0 does not yet have a stable programmatic API, users of tools like typescript-eslint or Vue/Svelte should use the @typescript/typescript6 compatibility package to run both versions side-by-side.

Install now:

npm install -g typescript

For the best experience, VS Code users should install the TypeScript 7 extension to enable the new language server immediately.