TypeScript 7, codenamed Project Corsa, is poised to dramatically accelerate development workflows with a complete overhaul of its compiler—potentially speeding up build times by as much as 10x. The update, detailed in December 2025, marks a fundamental shift, rewriting the core compiler in the Go programming language.
Faster Builds, Reduced Memory Footprint
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The new compiler promises significant performance gains for developers.
The revamped compiler, dubbed tsgo, leverages Go’s efficiency to deliver substantial speed improvements. According to the TypeScript team, full builds can now be up to ten times faster than previous versions, and the new system handles multiple projects with efficient parallel processing. The native language service, which powers features like code completion and refactoring within editors, is largely stable and available for immediate use.
Developers eager to test the preview can install it with this command:
npm install -g @typescript/native-previewStrictness Enabled by Default
One of the most impactful changes in TypeScript 7 is the automatic enabling of strictness settings. This represents a breaking change for projects upgrading from older versions, but reflects a commitment to type safety and adherence to industry best practices.
Why Go?
The decision to rebuild the compiler in Go sparked discussion within the developer community. A detailed FAQ explained that Go offers automatic garbage collection while remaining a highly native language. The existing TypeScript codebase’s functional style, with minimal classes, also made Go a natural fit compared to object-oriented alternatives.
Developer Reactions
On Hacker News, developers expressed enthusiasm about the potential performance improvements. One user noted, “Wow, this is huge! A 10x speedup is going to be game-changing for large TypeScript codebases like ours. I’ve been waiting for something like this – my team’s project takes forever to typecheck on CI and slows down our IDE.”
However, concerns were also raised regarding the migration path for tools that rely on the TypeScript compiler API. One developer questioned how the native compiler would be distributed and whether the compiler API would remain compatible, specifically mentioning transforms, the AST, LanguageService, Program, SourceFile, and Checker.
Early adopters have already reported positive results, with one Reddit commenter claiming a 75% reduction in typechecking time. Others welcomed the default strict mode settings, stating, “Strict enabled by default will be so nice. It’s such a pain to be working on a project and suddenly realize strict wasn’t enabled and you have a ton of fixes to make.”
Competing with Native Tooling
TypeScript 7’s native implementation positions it alongside other high-performance JavaScript tools built in native languages. Tools like esbuild (written in Go) and SWC and oxc (written in Rust) have already demonstrated the benefits of this approach. The TypeScript team’s move validates this architectural direction while maintaining full compatibility with the TypeScript language specification.
Released in 2012, TypeScript is a strongly typed programming language developed and maintained by Microsoft. It builds upon JavaScript by adding static type definitions, compiling to plain JavaScript that runs across browsers, Node.js, and other JavaScript runtimes. TypeScript enables developers to identify errors during compilation, enhances IDE support with features like code completion, and improves the maintainability of large codebases through explicit type contracts.
