JavaScript to TypeScript Converter
Convert JavaScript to TypeScript
JavaScript Input
TypeScript Output
What is TypeScript?
TypeScript is a typed superset of JavaScript that compiles down to plain JS your browser already runs.
It layers static typing on top of the same syntax defined by the ECMAScript spec — so you get IDE autocomplete, refactor safety, and compile-time checks without changing what your code does at runtime. See the Everyday Types handbook for the basics.
Everything happens in your browser. Nothing is uploaded to a server, so even proprietary code you would not normally paste into an online tool is safe here.
How to Use
Follow these steps.
Paste JavaScript
Paste your JavaScript code.
const x = 5;View TypeScript
See the converted TypeScript.
Download
Download your file.
Use Cases
Type Safety
Add type checking to your code.
Better IDE Support
Get better autocomplete and error checking.
Code Quality
Improve code quality and maintainability.
Large Projects
Better for large-scale projects.
FAQ
What is TypeScript?
Typed JavaScript — see the official handbook for a deeper introduction.
Do I need to learn TypeScript?
It extends JavaScript knowledge — if you are comfortable with modern JavaScript, you already know most of TypeScript.
Is it production-ready?
Yes
Can I use JavaScript with TypeScript?
Yes
Do I need a compiler?
Yes
Is it free?
Yes, open source
Related Tools
Other JavaScript tools: