Microsoft has shipped TypeScript 7.0. It is the first stable release built on a Go-based compiler. The rewrite delivers speedups of 8x to 12x on full builds. It also marks the end of the language’s decade-long history of being written in itself.
The headline number is speed. According to Microsoft Principal Product Manager Daniel Rosenwasser, “TypeScript 7 brings native code speed, shared memory multithreading, and a number of new optimizations that typically yield speedups between 8x and 12x on full builds.” The gains show up during development, not deployment, as DevClass notes.
That means faster file opening, quicker code search, and snappier auto-completion inside the editor. In many cases, the imported TypeScript Language Server was the culprit behind sluggish editors, not the editor itself.
The move was signposted earlier this year. Microsoft announced TypeScript 6.0 as the final JavaScript-based release, positioning it as a transition step before the Go port took over in 7.0.
Why the numbers matter
In Microsoft benchmarks, compiling VS Code (2.3 million lines) dropped from 125 seconds under TypeScript 6 to 10.6 seconds, an 11.9x jump. Sentry cleared 1.9 million lines in 15.7 seconds, while Playwright’s 528,000 lines took 1.47 seconds. Independent write-ups peg the improvement at roughly an order of magnitude, with memory use roughly halved.
At Slack, developers previously couldn’t run a full type-check locally and offloaded the job to the CI server. With TypeScript 7, that check runs on the developer’s machine again.
Why Go, not C# or Rust
For a Microsoft team, Go is a surprising pick over its own C# or the increasingly popular Rust. Lead architect Anders Hejlsberg explained that Go was “the lowest level language we can get to that gives us full native-code support on all platforms,” and strong at concurrency.
Team lead Ryan Cavanaugh added structural reasons: Go’s syntax resembles JavaScript, easing maintenance across both codebases, and its memory model lets the team largely sidestep the garbage collector during compilation. Go, released open source in 2009, has long been the backbone of cloud-native software, valued for stability in large-scale projects. The native compiler exposes concurrency flags such as --checkers and --builders to tune parallel type-checking.