On July 8, 2026, Microsoft released TypeScript 7.0 – the native compiler written in Go. The speed figures are extraordinary and they withstand the test. Nevertheless, the answer to the question “should we switch?” for most projects is still: joy. The reason is not in the headlines, but in a subset of the release notes.
The Numbers That Are Right
Microsoft has measured the benchmarks against real, large codebases. Build time with the default settings:
- VS Code: 125.7 s → 10.6 s (factor 11.9)
- Sentry: 139.8 s → 15.7 s (factor 8.9)
- Playwright: 12.8 s → 1.47 s (factor 8.7)
With more parallel checkers ()--checkers 8VS Code even goes down to 7.5 seconds – factor 16.7. There are also reliable figures from practice: Slack reports that the typecheck in the CI has fallen from 7.5 to 1.25 minutes and the time in the merge queue has been reduced by 40 percent.
Even more noticeable is the effect in the editor: The number of failed language server commands fell by over 80 percent, the crashes by over 60 percent, according to Microsoft. In VS Code, it used to take 17.5 seconds from opening a file to the first error display – now it’s under 1.3 seconds.
However, one expectation should be dampened: The Memory consumption falls by only 6 to 26 percent, not by the factor that speed suggests. Anyone who wants to switch to the CI because of RAM problems will be disappointed.
The catch: TypeScript 7.0 does not have an API
Here's the key phrase, and it literally comes from Microsoft: TypeScript 7.0 is shipped without API; A new – and different – API should come only with 7.1.
This sounds like a detail for tool makers, but it is the reason why a large part of the ecosystem cannot yet take part. Because each The tool that programmatically integrates the TypeScript compiler depends on this API:
- typescript-eslint does not yet support TypeScript 7 – anyone using type-based linting is blocked.
- Vue, Svelte, Astro and MDX according to Microsoft, TypeScript 7 cannot be used for the time being.
- Angular cannot change its template-type-checking to it.
- Everything that imports the compiler – code generation, own transformer, ts-node, ts-jest – has to wait.
Microsoft is remarkably open and recommends even a hybrid operation: TypeScript 7 for the Typecheck in CI and Build, the parallel installable TypeScript 6 (tsc6) in the editor and for the linting chain. This is unspectacular, costs almost nothing – and picks up exactly the profit that counts in everyday life: shorter CI times.
What is quietly broken during the changeover
TypeScript 7 removes contaminated sites without fallback. Hard excluded among others target: es5, moduleResolution: node, baseUrl, the module formats AMD/UMD/SystemJS and the namespace-like module-Keyword.
But the new defaults are more dangerous than the hard errors, because they change the behavior without an error message. strict is now on by default, module stands on esnext – and above all: types by default is empty instead of “everything”. Ambient types must therefore be explicitly declared. Experience shows that this is the most common breaking point in grown projects.
A special case are JavaScript projects that are typed by JSDoc: The native compiler has significantly curtailed this support. Whoever works like this, should leave the switch completely for the time being.
The route foreseen by Microsoft is TypeScript 6 (published in March 2026, the last JavaScript-based compiler). It marks as obsolete exactly what 7.0 then removes. If you migrate to 6 and are clean there, then compile without surprises under 7.
Our recommendation
Switch now is worthwhile if you have a large, pure TypeScript codebase, modern configured (ESM, strict), without editor plugins in the critical path – and when long CI typecheck times hurt. The factor 8 to 12 is real.
You should still wait for Vue, Svelte, Astro or Angular projects, type-based linting and wherever the compiler is programmatically integrated. For these projects, the relevant version is not 7.0, but 7.1 with the new API – Microsoft does not specify a date, with a cadence of three to four months, the end of 2026 is expected.
The pragmatic middle ground for almost everyone: introduce TypeScript 7 in the CI, leave TypeScript 6 in the editor. This reduces the build times today without breaking the tool chain.
If you want to know whether the change is worthwhile for your specific codebase, we talk about it – see Custom Software Development.
Sources: Microsoft DevBlog "Announcing TypeScript 7.0" (8 July 2026) and "Announcing TypeScript 6.0" (23 March 2026); current stable version: 7.0.2. as of 6 August 2026.
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