TypeScript 7 launches with Go-based rewrite, delivering up to 17x faster compilation

Microsoft has officially released TypeScript 7, marking a major architectural shift by rewriting the language's implementation in Go instead of TypeScript itself. The primary goal of the rewrite was to dramatically speed up compilation, with benchmarks showing compile times improving by roughly 8x to 17x across major codebases such as VS Code, Sentry, and Playwright. Memory usage has also dropped by up to 26% depending on the project. New features include parallel parsing, type-checking, and emitting via experimental --checkers and --builders flags, a --singleThreaded mode for debugging, and an upgraded --watch mode using a Go-ported version of Parcel's file-watcher. Since VS Code itself runs on TypeScript, users can expect noticeably faster editor operations, with first-error detection in VS Code reportedly dropping from around 17.5 seconds to under 1.3 seconds.