News

Microsoft Supercharges TypeScript

• By John K. Waters
• March 12, 2025

For years, TypeScript has been the de facto superset of JavaScript, beloved by developers for its type safety, better tooling, and scalability. But for all its benefits, one nagging issue has remained: performance.

Anyone who has worked on a massive TypeScript project—think millions of lines of code, sprawling enterprise apps, or AI-driven tools—knows the pain: slow editor response times, long build processes, and memory-hungry compilers that could choke even high-end machines. This week, Microsoft unveiled its answer: a complete native port of TypeScript, promising 10x faster build times, dramatically reduced memory usage, and near-instant error checking.

Anders Hejlsberg, the creator of TypeScript and a Technical Fellow at Microsoft, described it simply in a blog post: "We’ve begun work on a native port of the TypeScript compiler and tools. The impact? A faster, leaner, more powerful development experience, one that unlocks entirely new possibilities for TypeScript developers."

A Compiler Reborn

Since its launch in 2012, TypeScript has been written in TypeScript itself, which compiles down to JavaScript. It’s a clever, self-hosting solution—but as projects grew in size, its performance bottlenecks became painfully clear. The cost of loading massive projects, analyzing types, and performing refactors was high, forcing developers to choose between a fast startup time or a full-featured editor experience.

The new native implementation of TypeScript eliminates these trade-offs. Instead of compiling to JavaScript, Microsoft is rewriting the TypeScript compiler and tools in a natively compiled language, a move that drastically reduces load times and memory overhead.

According to Microsoft’s internal benchmarks, the speedups are impressive:

"We’re incredibly excited about the opportunities that this massive speed boost creates," Hejlsberg said. "Features that once seemed out of reach are now within grasp. This native port will be able to provide instant, comprehensive error listings across an entire project, support more advanced refactorings, and enable deeper insights that were previously too expensive to compute. This new foundation goes beyond today’s developer experience and will enable the next generation of AI tools to enhance development, powering new tools that will learn, adapt, and improve the coding experience. The results? Massive reductions in build times across the board. The biggest improvement, however, isn't just in build speeds. It's in how developers interact with TypeScript in real time."

Near-Instantaneous Development

Most of a developer’s time is spent inside an editor, where responsiveness is everything. With the new native TypeScript compiler, Microsoft is reporting:

• 8x faster editor startup times
• 50% less memory usage
• Instant “Find All References” and renaming across large projects

For developers, this means snappier autocomplete, faster type checking, and near-zero lag when refactoring or navigating large codebases. The days of waiting for the editor to "catch up" are finally over.

AI and TypeScript: A New Era

Another major benefit of this overhaul? AI-powered developer tools.

Modern AI coding assistants—such as GitHub Copilot and OpenAI’s Codex—rely on deep semantic understanding of a codebase. This requires quick access to type information, function signatures, and relationships between components.

With the new TypeScript compiler reducing latency, Microsoft says this will enable the next generation of AI-powered coding experiences. Expect more intelligent code suggestions, advanced debugging, and real-time code analysis at a scale never before possible.

What’s Next? The TypeScript 7.0 Roadmap

Microsoft has laid out a clear versioning roadmap for this transition.

• TypeScript 6.x will continue to be based on the existing JavaScript codebase, supporting current projects.
• TypeScript 7.0, the first fully native release, is expected by the end of 2025.
• Microsoft will maintain both versions for some time, allowing developers to transition at their own pace.

For those eager to get a hands-on preview, the new TypeScript compiler is already available on GitHub, with a working implementation of tsc (the TypeScript compiler) and a basic language service.

A Revolution for the JavaScript Ecosystem

JavaScript remains the dominant programming language of the web, and TypeScript has become its most powerful companion. By supercharging TypeScript’s performance, Microsoft is redefining what’s possible for developers, from faster builds to AI-assisted coding experiences.