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Cheerp is an open-source, commercial C/C++ compiler for Web applications. It allows to compile virtually any C/C++ code to WebAssembly and JavaScript.

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Main project link:

This repository is the main reference for documentation, issue tracking, and release notes. The main component is on Github: cheerp-compiler, while other repositories are at cheerp-newlib, cheerp-utils and cheerp-libs

What is Cheerp

Cheerp is a C/C++ compiler for the Web, based and integrated into the LLVM/clang infrastructure, and featuring numerous custom optimisation steps to maximise performance and minimise size of the compiled JavaScript/WebAssembly output. Thanks to this, Cheerp is the best performing, most optimised C++ to WebAssembly compiler available on the market.

Cheerp is used primarily to port existing C/C++ libraries and applications to HTML5, but can also be used to write high-performance Web applications and WebAssembly components from scratch. C/C++ gets optimised and compiled into JavaScript/WebAssembly, and can easily be integrated in a web page.

Diagram of Cheep usage

What is unique about Cheerp?

Cheerp enables C/C++ code to be compiled to a combination of WebAssembly and JavaScript (possibly asm.js when targeting legacy browsers). Compared to alternative C/C++ compilers for web applications such as Emscripten, Cheerp:

  1. Generates faster WebAssembly code, but can also compile to a JavaScript output with dynamic memory (garbage-collectible output), zero-overhead DOM manipulation and access to WebApis and superior C++-JavaScript interoperability.
  2. Allows to compile a single code base into a combination of WebAssembly and JavaScript by (optionally) tagging portions of the code with [[cheerp::genericjs]] and [[cheerp::wasm]].
  3. Generates smaller WebAssembly outputs.

Cheerp is open-source software and is free to use for GPLv2 projects. Non-copyleft commercial licenses, commercial support and consulting packages are available from Leaning Technologies.

Get started

First time user? We recommend following the Getting started page, that will guide though this steps:

Or look at the sidebar to find lots of useful materials

Bugs and Questions

You can get in touch with us using our Gitter chat, or by filing a bug on our Issue tracker.