TypeScript 7.0 Beta Released

Microsoft has released TypeScript 7.0 Beta. The new implementation is a native port of the existing compiler to Go, targeting performance often about 10x faster than TypeScript 6.0.

It is currently distributed as a separate package. Install it with npm install -D @typescript/native-preview@beta, then run tsgo instead of tsc. Although the release is in beta stage, they explained it's stable enough to use right away in everyday development and CI.

The key characteristics are as follows.

• The new codebase is closer to a systematic port than a rewrite.
• The type-checking logic is structurally identical to TypeScript 6.0.
• Speed has been improved by parallelizing parsing, type checking, and emit.
• Execution can be adjusted with options like --checkers, --builders, and --singleThreaded.

In terms of compatibility, the goal is to preserve TypeScript 6.0-based behavior, but some default value changes and cleanup of deprecated options may cause differences in existing projects. In particular, settings related to rootDir, types, module, and strict need to be checked during migration.

Also, by making JS/JSDoc handling more consistent with the way TS files are analyzed, some old Closure-style syntax and special-case handling have been removed. Codebases centered on JS + JSDoc need a separate review.

For editors, a VS Code TypeScript Native Preview extension is provided. Since it uses the same foundation as the CLI, performance improvements also carry over to auto-import, hover, inlay hints, code lens, JSX linked editing, and more.

However, a stable programmatic API is not yet available, and this is targeted for after TypeScript 7.1. The stable version is planned within about 2 months, with the RC coming a few weeks before that.