Compiling TypeScript with tsc watch

Watch and recompile any TypeScript file on write, no project required, with --watch:

$ tsc <your-file>.ts --watch

This is a great hack to tell if you’ve written compilable TypeScript, without other tooling. It returns:

Starting compilation in watch mode.

Now, when you write your tutorial file, the compiler compiles, giving near-instant feedback.

Something that trips people up: without a tsconfig.json, tsc uses the compiler’s default options, and it still emits .js next to your .ts. Watch mode will keep rewriting that output on every write.

If you only want a compile check and no artifacts, add --noEmit:

$ tsc <your-file>.ts --watch --noEmit

That keeps the same feedback loop without any collateral JavaScript file creation.

TypeScript documentation - tsc CLI options