Microsoft is moving closer to a major architectural shift for TypeScript, with a native implementation of the language expected to arrive in early 2026. The upcoming TypeScript 7.0 release replaces the long-standing JavaScript-based compiler and language service with a new implementation written in Go, aiming to deliver faster performance, lower memory consumption, and better use of parallel processing.
Before that transition is complete, Microsoft plans to ship TypeScript 6.0 as a transitional milestone. This version will serve as the final release built on JavaScript and is designed to help developers move smoothly from the current 5.9 branch to the new native platform. According to Microsoft, TypeScript 6.0 will not evolve into a longer release line and will exist mainly to align existing projects with the changes introduced in 7.0.
The native effort, internally known as Project Corsa, was first announced earlier this year and is progressing steadily. In a blog update published on December 2, Daniel Rosenwasser, principal product manager for TypeScript at Microsoft, described the work as extensive but productive. Both TypeScript 6.0 and 7.0 are currently expected to become available in early 2026, and the Go-based source code is openly accessible in the TypeScript-go repository on GitHub.
Significant advancements have already been made in the language service that powers editor features such as autocomplete, diagnostics, and navigation. Most of the functionality developers rely on during daily coding is already operational in the native version, although some remaining components are still being migrated. Parts of the system have also been redesigned to improve stability and to take advantage of shared-memory concurrency. Developers can experiment with the latest preview of the native language service through an extension available in the Visual Studio Code Marketplace.
Progress on the compiler itself has been equally notable. Type checking in TypeScript 7.0 is nearly complete, and Microsoft reports that the new compiler closely matches the behavior of the existing one. A common concern among developers has been whether the native compiler can reliably detect the same errors as TypeScript 5.9. Based on extensive testing, the answer appears to be yes. Out of roughly 20,000 compiler test cases, about 6,000 intentionally generate errors, and TypeScript 7.0 matches those results in nearly every scenario, missing only a small number of edge cases. This makes the new compiler suitable for real-world validation tasks even at its current stage.
Beyond basic type checking, the command-line tooling has reached near feature parity. Capabilities such as incremental builds, project references, and build mode support have already been implemented and are functioning as expected in the Go-based compiler.
TypeScript 7.0 will also clean up legacy behavior by removing options and flags that are scheduled for deprecation in TypeScript 6.0. Microsoft has published a list of these upcoming removals in the project’s issue tracker to help teams prepare in advance. Some areas, however, are still under development. JavaScript emission, watch mode, and certain API-related workflows are not yet fully implemented in the native pipeline. For teams that only rely on type checking and do not require JavaScript output, running builds with the new tsgo tooling is already viable.
It is also worth noting that the new Corsa-based release will not support the existing Strada API. A replacement API is planned, but it remains under active development and is not yet finalized.
Microsoft has emphasized that TypeScript 6.0 is intended strictly as a compatibility bridge rather than a long-term release. No TypeScript 6.1 version is currently planned, although maintenance updates may be issued if necessary. The overarching goal is to keep type-checking behavior as consistent as possible between versions 6.0 and 7.0, minimizing disruption for developers as the platform transitions to its new native foundation.
