TypeScript 7.0 Released: Massive Performance Leap Powered by Go Rewrite

Microsoft released TypeScript 7.0, featuring a fundamental architectural overhaul. The compiler was almost entirely rewritten in Go instead of JavaScript/Node.js, and workflows are now parallelized rather than executed sequentially. These changes deliver compilation speeds approximately ten times faster than TypeScript 6.0 across various projects, alongside meaningful reductions in memory consumption.

Benchmarks demonstrate the performance gains across real-world codebases. VS Code compiles 11.9 times faster—reducing build time from over two minutes to roughly 11 seconds—while Sentry, Bluesky, and Playwright show speedup factors near 9x, and tldraw projects achieve 7.7x faster builds. Opening a file with errors in VS Code drops from 17.5 seconds to under 1.3 seconds for error display. Memory usage also improves across projects: down 6 percent for Sentry, 18 percent for VS Code, and over 25 percent for Bluesky.

The final release maintains compatibility with TypeScript 6.0, allowing parallel installation via npm. The standard tsc command now invokes the new compiler, while the @typescript/typescript6 compatibility package provides tsc6 and the legacy TypeScript 6.0 API for existing tools to continue functioning unchanged. Microsoft focused the production release on stability improvements, enhanced watch mode, fuller editor support, and clearer migration paths for the TypeScript ecosystem. A new API is planned for TypeScript 7.1.