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Wasmer is a Standalone JIT WebAssembly runtime, aiming to be fully compatible with Emscripten, Rust and Go.

Install Wasmer with:

curl https://get.wasmer.io -sSfL | sh


wasmer can execute both the standard binary format (.wasm) and the text format defined by the WebAssembly reference interpreter (.wat).

Once installed, you will be able to run any wasm module (including Nginx!):

wasmer run examples/nginx/nginx.wasm -- -p examples/nginx -c nginx.conf

Building & Running

To build this project you will need Rust and Cargo.

# checkout code
git clone https://github.com/wasmerio/wasmer.git
cd wasmer

# install tools
# make sure that `python` is accessible.
cargo install


Thanks to spectests we can assure 100% compatibility with the WebAssembly spec test suite.

Tests can be run with:

make test

If you need to re-generate the Rust tests from the spectests you can run:

make spectests


Wasmer is an open project guided by strong principles, aiming to be modular, flexible and fast. It is open to the community to help set its direction.

Below are some of the goals (written with order) of this project:

  • It should be 100% compatible with the WebAssembly Spectest
  • It should be fast (partially achieved)
  • Support Emscripten calls (on the works)
  • Support Rust ABI calls


If you would like to know how Wasmer works under the hood, please visit our ARCHITECTURE document.