TypeScript 7.0 GA: Go Compiler Cuts Full Builds 11.9x
TypeScript 7.0, the Go-based native compiler, hits GA with 8-12x faster builds and first-error times under 1.3s in VS Code, but ships no stable API, so tooling stays on 6.x via the @typescript/typescript6 alias.
TypeScript 7.0 reaches GA, and the Go-based port delivers the numbers. Full builds drop 8-12x: VS Code from 125.7s to 10.6s, Sentry from 139.8s to 15.7s, Bluesky from 24.3s to 2.8s, Playwright from 12.8s to 1.47s. The --checkers flag controls parallelism, default 4; 8 checkers takes VS Code to 7.51s, a 16.7x improvement. Memory use drops 6-26%. VS Code first-error time falls from 17.5s to under 1.3s, and Slack's CI went from 7.5 minutes to 1.25.
The economics shift with it. Full-project type checks stop being the thing you skip in CI when a check that used to eat minutes runs in seconds. Editor semantics match compiler semantics, so editor squiggles and build failures no longer diverge. Semantic highlighting, sort imports, and remove unused imports are in.
Read the caveat before you flip your toolchain: 7.0 ships no stable API. typescript-eslint and every other compiler-API consumer stays on 6.x. Microsoft publishes @typescript/typescript6, installable as typescript@npm:@typescript/typescript6, so you run both: 7 for checking and building, 6 for anything that touches the API. The new API lands in 7.1.
Defaults change: strict on, module esnext. The deprecations that already turned into hard errors with no-op behavior now fail loudly: target es5, downlevelIteration, moduleResolution node, and baseUrl are unsupported, not warned. Code that compiles cleanly on 6.0 should compile identically, but configs that still set the deprecated flags hard-error and need cleanup. Verify your tooling against 7 before making it the repo-wide compiler.