Starts and ends with JavaScript
TypeScript starts from the same syntax and semantics that millions of JavaScript developers know today. Use existing JavaScript code, incorporate popular JavaScript libraries, and call TypeScript code from JavaScript.
TypeScript compiles to clean, simple JavaScript code which runs on any browser, in Node.js, or in any JavaScript engine that supports ECMAScript 3 (or newer).
Strong tools for large apps
Types enable JavaScript developers to use highly-productive development tools and practices like static checking and code refactoring when developing JavaScript applications.
Types are optional, and type inference allows a few type annotations to make a big difference to the static verification of your code. Types let you define interfaces between software components and gain insights into the behavior of existing JavaScript libraries.
State of the art JavaScript
TypeScript offers support for the latest and evolving JavaScript features, including those from ECMAScript 2015 and future proposals, like async functions and decorators, to help build robust components.
These features are available at development time for high-confidence app development, but are compiled into simple JavaScript that targets ECMAScript 3 (or newer) environments.
Get TypeScript
Node.js
The command-line TypeScript compiler can be installed as a Node.js package.
- Install
- npm install -g typescript
- Compile
- tsc helloworld.ts
Visual Studio
See TypeScript in Action
Open Source
TypeScript is being developed on GitHub. The TypeScript compiler is implemented in TypeScript and can be used in any JavaScript host.
Read the specification on GitHub or download it as a docx or pdf.
Join the #typescript Twitter discussion and follow the GitHub project.
Why TypeScript?
We love TypeScript for many things… With TypeScript, several of our team members have said things like 'I now actually understand most of our own code!' because they can easily traverse it and understand relationships much better. And we’ve found several bugs via TypeScript’s checks.”
“One of Ionic's main goals is to make app development as quick and easy as possible, and the tooling support TypeScript gives us with autocompletion, type checking and source documentation really aligns with that.”
“TypeScript helped us to reuse the team’s knowledge and to keep the same team velocity by providing the same excellent developer experience as C# ... A huge improvement over plain JavaScript.”
“By combining Aurelia with TypeScript for modern web, mobile and desktop development, we've seen what is perhaps the most beautiful and elegant app development workflow to date.”
TypeScript has helped ensure that Dojo 2 will be built on rock solid foundations, which will make enterprise development better. TypeScript gives us all the benefits of ES6, plus more productivity, … and responsive support from the TypeScript team.”
“TypeScript is a smart choice when writing a modern web- or JavaScript-based application. TypeScript’s carefully considered language features and functionality, and its consistently improving tools, result in a terrifically productive development experience.”
See more friends of TypeScript