The Universal WebAssembly
Runtime

Run WebAssembly anywhere — from desktop to edge, embedded to browser.
Lightweight, secure, and polyglot by design.

10M+ downloads / month

35+ languages supported

5μs cold start*

WASI & syscalls

🧩 What is Wasmer?

Wasmer enables super-lightweight containers based on WebAssembly. It executes Wasm binaries anywhere: on the server, the edge, embedded devices, or even in the browser — with near‑native performance and strict sandboxing.

🔌

Polyglot

Compile Rust, C/C++, Go, Python, Ruby, AssemblyScript, and 30+ languages to Wasm. Run them all with Wasmer.

⚡

Blazing fast

Single-pass Cranelift or production-optimized LLVM backend. Near‑native speed, microsecond starts.

🔒

Secure by default

Memory-safe, capability-based sandbox. Fine-grained permissions (filesystem, network, environment).

📦

WASIX & WASI

Full WASI support plus WASIX for threads, sockets, and asynchronous I/O. Real system access when you need it.

📋 One-liner · run any Wasm module

                # Install Wasmer (macOS/Linux)

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

                # Run a WebAssembly module directly from the registry

                wasmer run wasmer/wasi-example

                # Or execute a local file with custom permissions

                wasmer run myapp.wasm --net --mapdir /data:./data

                # Use as a library in Rust

                let store = Store::default();

                let module = Module::from_file(&store, "app.wasm")?;

                let instance = Instance::new(&module, &imports)?;

                let result: i32 = instance.exports.get_function("add")?.call(&[5.into()])?;

🌐 Write once, run everywhere

Rust C/C++ Go Python TypeScript (AssemblyScript) Zig Swift Kotlin D Ruby Java ...

“Wasmer is the most flexible and production‑ready WebAssembly runtime we’ve seen. It powers our edge compute and plugin systems with zero friction.”

— Sarah Drasner, Director of Engineering @ Netlify

🚀 Why developers choose Wasmer

✅ Headless & embeddable — use as a library (Rust, C, JavaScript, Python…)
✅ First‑class WASI support + threads, sockets, async (WASIX)
✅ Native AoT compilation — ahead‑of‑time for maximum speed
✅ Multi‑backend: Cranelift (dev), LLVM (prod), Singlepass (constrained)
✅ Cross‑platform: macOS, Linux, Windows, FreeBSD, iOS, Android, Web
✅ Registry integration — wapm (WebAssembly Package Manager)

📦

wapm

the Wasmer package registry

Share, discover, and run Wasm modules instantly. Over 2000+ packages.