TypeScript 7: The Go Compiler Is Here and It’s Fast

TypeScript 7 is out

The biggest change in TypeScript’s history has shipped. TypeScript 7.0, released in July, is the first stable version built on a native compiler written in Go – the project Microsoft first announced as “Project Corsa” in March 2025. The language you write doesn’t change; the tool that checks and compiles it does, and it’s dramatically faster.

We covered why TypeScript has become the default for new projects in TypeScript in 2026. This post is about the compiler underneath it.

How much faster?

Microsoft’s headline figure is 8x to 12x faster full builds on large projects. That comes from native code, shared-memory multithreading and a set of new optimisations. The gains aren’t just in tsc runs: project loading, diagnostics and editor operations like find-all-references benefit too, once the new language service is in use (more on that below).

For small projects you’ll barely notice. For a monorepo where type-checking takes minutes in CI, this is the kind of change that alters how you work.

Installing it

During the previews the native compiler shipped as a separate tsgo binary. That’s gone for the stable release: TypeScript 7 is published as the normal typescript package and still uses the tsc command, so most projects upgrade with one line:

npm install -D typescript@7
npx tsc --version

Your tsconfig.json carries over. Run a full tsc --noEmit before and after the upgrade and compare the output – a clean diff is the best evidence the upgrade is safe.

What isn’t ready yet

A few things are still catching up, and they matter more than the speed headlines:

• No stable programmatic API. Microsoft has said a stable compiler API won’t arrive until TypeScript 7.1 at the earliest, “several months” out. Anything that imports the compiler as a library – code generators, some lint rules, custom transformers – may not work on 7.0 yet.
• The editor experience is unchanged for now. The Go-based language service is still being ported, so VS Code keeps using the JavaScript-based service by default. If you want to try the native one, there’s a TypeScript Native Preview extension.
• Ecosystem tools need time. Bundlers, test runners and frameworks that only strip types are generally fine; tools that do their own type-aware work need to support 7 explicitly.

The TypeScript 6 bridge

Microsoft planned for this. TypeScript 6.0 was positioned as a bridge release – the last version with the JavaScript-based compiler, kept close to 7.0 in behaviour so projects could move to 6 first and then make a smaller jump. For tools that still need the old API, there’s a compatibility package, @typescript/typescript6, that can sit alongside TypeScript 7.

A safe upgrade path

1. Get onto TypeScript 6 first and fix any deprecation warnings.
2. Upgrade a branch to TypeScript 7 and run your full type-check and test suite.
3. Check every tool in your chain that imports typescript directly; pin @typescript/typescript6 for any that aren’t ready.
4. Switch CI first – that’s where the build-time savings pay off most – and let editors follow once the native language service is stable.
5. Treat third-party claims about changed compiler defaults with caution and check the official release notes before relying on them.

Should you upgrade now?

For applications whose toolchain only needs tsc to type-check, yes – the speed-up is real and the risk is low. For libraries and tooling that lean on the compiler API, wait for 7.1. Either way, TypeScript 7 is where the language is going, and getting your CI onto it is one of the cheapest performance wins available this year.