@swc/core

What is @swc/core?

The @swc/core package is a super-fast compiler written in Rust that allows for transforming ECMAScript 2015+ code into a backwards compatible version of JavaScript that can be run in older browsers or environments. It is designed to be highly performant and offers features such as transpilation, minification, and source maps generation.

What are @swc/core's main functionalities?

JavaScript/TypeScript Transpilation

Transpiles TypeScript or modern JavaScript to a specified ECMAScript target version. This example demonstrates transpiling TypeScript code to ES5.

require('@swc/core').transformSync('const x: number = 1;', { jsc: { parser: { syntax: 'typescript' }, target: 'es5' } });

Code Minification

Minifies JavaScript code to reduce file size, which is beneficial for production environments. This example shows how to minify a simple expression.

require('@swc/core').transformSync('const x = 1 + 2;', { minify: true });

Source Maps

Generates source maps for the transformed code, aiding in debugging by mapping the transformed code back to the original source code. This example demonstrates generating a source map for a file named 'input.js'.

require('@swc/core').transformFileSync('input.js', { sourceMaps: true });

Other packages similar to @swc/core

babel-core

Babel is a widely used JavaScript compiler that also allows for transforming modern JavaScript into backward compatible versions. Compared to @swc/core, Babel is more established with a larger ecosystem of plugins, but @swc/core is known for its superior performance due to being written in Rust.

typescript

The TypeScript compiler not only provides type checking but also has the capability to transpile TypeScript code to JavaScript, similar to the transpilation feature of @swc/core. However, TypeScript does not focus on minification or other optimizations that @swc/core offers.

esbuild

Esbuild is a fast JavaScript bundler and minifier. It shares similar goals with @swc/core in terms of performance and efficiency. While both are focused on speed, esbuild emphasizes on bundling and has a different set of features compared to the more transpilation-focused @swc/core.

README

Make the web (development) faster.

SWC (stands for Speedy Web Compiler) is a super-fast TypeScript / JavaScript compiler written in Rust. It's a library for Rust and JavaScript at the same time. If you are using SWC from Rust, see rustdoc and for most users, your entry point for using the library will be parser.

Also, SWC tries to ensure that

If you select the latest version of each crates, it will work

for rust users.

MSRV of crates is currently nightly, but we will support stable rustc again in the future.

---

If you are using SWC from JavaScript, please refer to docs on the website.

Documentation

Check out the documentation in the website.

Features

Please see comparison with babel.

Performance

Please see benchmark results on the website.

Supporting swc

SWC is a community-driven project, and is maintained by a group of volunteers. If you'd like to help support the future of the project, please consider:

• Giving developer time on the project. (Message us on Discord (preferred) or Github discussions for guidance!)
• Giving funds by becoming a sponsor (see https://opencollective.com/swc)!

Contributing

See CONTRIBUTING.md. You may also find the architecture documentation useful (ARCHITECTURE.md).

License

SWC is primarily distributed under the terms of the Apache License (Version 2.0).

See LICENSE for details.