Wasmtime

A small and efficient runtime for WebAssembly & WASI

Start using the latest developments in WebAssembly and WASI with the Wasmtime runtime.

Installing Wasmtime

It looks like you’re running macOS or Linux. To download and install Wasmtime, run the following in your terminal, then follow the on-screen instructions.

curl https://wasmtime.dev/install.sh -sSf | bash

It looks like you’re running Windows. To install Wasmtime, download and run the following, and then follow the onscreen instructions.

Wasmtime Installer

If you’re a Windows Subsystem for Linux user run the following in your terminal, then follow the on-screen instructions to install Wasmtime.

curl https://wasmtime.dev/install.sh -sSf | bash

If you’re running macOS or Linux, download and install Wasmtime by running the following in your terminal and following the on-screen instructions.

curl https://wasmtime.dev/install.sh -sSf | bash

If you are running Windows, download and run the Wasmtime Installer then follow the on-screen instructions.


Alternatively, you can also download releases for all supported platforms from the Wasmtime GitHub page.

Embedding Wasmtime

Wasmtime implements the standards-track Wasm-C-API.

The Bytecode Alliance also hosts Wasmtime embedding APIs for a number of languages:

See our documentation on language embeddings for details on how to get started with these.

In addition, embedding APIs for other languages are maintained outside the Bytecode Alliance:

Targeting Wasmtime

We're maintaining WASI toolchains for Rust and C/C++. For an introduction to those, please see our WASI tutorial, which has sections on C and Rust.

See our collection of examples for some examples of content to run in, and ways to use Wasmtime.

For more information on WASI, see the WASI homepage.

Building Wasmtime

System requirements

Building Wasmtime requires a recent version of the Rust compiler and toolchain, and a C++ toolchain released after 2007.

Downloading and building the sources

With those requirements in place, you can download and build the Wasmtime source:

git clone --recurse-submodules \
    https://github.com/bytecodealliance/wasmtime.git
cd wasmtime
cargo build --release