Hi, I'm Dmitry

Full-stack web developer with a passion for UX and building products.

Vancouver, Canada and remote. He/him.

Faster TypeScript compilation in VSCode

September 08, 2020

It’s no secret that TypeScript can get slow in VSCode. Especially so for code-bases with non-trivial type inference (I’m looking at you, ChakraUI).

Ever found yourself waiting for the compiler to catch up with you as you type new code or fix errors? This quickly gets frustrating, what’s worse it slows down your feedback loops.

Here I’m sharing a simple tip that saved me hours of my life over the last 3 years working with TypeScript codebases (especially large ones!).

I wish I knew it earlier when I was just getting started with TypeScript…

How to fix slow TypeScript compilation

Here’s the trick:

  1. Run a separate TypeScript process in watch mode in a terminal tab.
  2. Keep it running as you write code — it’ll respond to changes and highlight errors a lot faster compared to VSCode.

Making TypeScript compile faster in VSCode

In my experience, the difference can be striking (see the screenshot). It seems to depend on the project and npm libs it’s using, but the general pattern is pretty consistent across different projects and TS versions I worked with.

Integrate with your TypeScript project

Here’s how to make it more convenient in your TypeScript project, step-by-step:

  1. Add these 2 NPM scripts to your package.json:
"scripts": {
  ...
  "typecheck": "tsc",
  "typecheck:watch": "tsc -w"
  ...
}
  1. Now run npm run typecheck:watch in a terminal tab (I like to do it in VSCode’s Terminal panel to keep things in the same window).

This starts a separate TypeScript process in the watch mode. It’ll take some time to start, but it’ll be much faster to re-compile your code incrementally as you change your code.

  1. Use npm run typechek if only need to do the check once. It’ll run faster than the watch mode. I find it handy e.g. before deploying to make sure the build will be succesful.

🙌 That’s it!

I hope this tip helps you to have a faster TypeScript workflow and to be more happier at work (it certainly helped me!).