Progress on TypeScript 7 – December 2025
9 days ago
- #Performance
- #Compiler
- #TypeScript
- TypeScript team is porting the compiler and language service to native code (Project Corsa, soon TypeScript 7.0) for better performance, memory usage, and parallelism.
- Native previews are now fast, stable, and usable in editors, with most features like code completions, go-to-definition, and rename reimplemented.
- TypeScript 7.0's compiler is nearly complete in type-checking, with major parity in features like --incremental and --build mode, offering significant speedups (up to 10x faster).
- TypeScript 7.0 will remove deprecated behaviors and flags from TypeScript 6.0, requiring some tsconfig.json updates for compatibility.
- JavaScript emit pipeline and --watch mode in TypeScript 7.0 are not fully complete, with limited support for older runtimes and decorators.
- TypeScript 6.0 will be the last JavaScript-based release, serving as a bridge to TypeScript 7.0, with limited future updates.
- Language service issues are being reset due to the new architecture, requiring new issue reports for the native preview.
- Users are encouraged to try the native preview extension for VS Code and provide feedback to help prioritize remaining work.