# Wasmtime

A lightweight WebAssembly runtime that is fast, secure, and standards-compliant

Repository: https://github.com/bytecodealliance/wasmtime
Canonical: https://ross.abutalabs.com/products/wasmtime
Homepage: https://wasmtime.dev/
Language: Rust
License: Apache-2.0
License Family: permissive
Topics: wasm, jit, sandbox, cranelift, wasi, wasmtime, webassembly, runtime, rust, aot, standalone, lightweight, portable
Last push: 2026-08-26T22:23:00+00:00
Link (homepage): https://wasmtime.dev/
Link (site_page): https://docs.wasmtime.dev/

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 3291, "days_push": 7, "days_rel": 9, "gap_med": 1.0, "n_releases_24m": 101}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 18570, forks 1807 (observed 2026-08-28T04:11:26.811568+00:00)

## What it is
Wasmtime is a standalone WebAssembly runtime built on the Cranelift code generator, usable both as a CLI and as an embeddable library. It supports WASI and the Component Model with a focus on speed, security, and standards compliance.

## Use cases
- run webassembly modules outside the browser
- embed a wasm runtime in my application
- execute wasi programs from the command line
- sandbox untrusted code with wasm
- compile wasm ahead-of-time for fast startup
- run webassembly components on linux windows and macos

## When to choose
- you need a fast, secure, standards-compliant wasm runtime
- you want to embed wasm execution in Rust, C, Python, Go, or .NET apps
- you need WASI or Component Model support
- you want ahead-of-time compilation and low-overhead instantiation

## When to avoid
- you need to run wasm in a web browser (use the browser's built-in engine)
- you need JavaScript-specific wasm tooling rather than a runtime
- you require a runtime written in a language other than Rust for your stack

## Facets
- artifact type: library
- maturity: stable
- function: wasm, interpreter, cli, compiler
- domain: developer-tools, compilers, security, cross-platform
- platform: windows, rust, cli, cross-platform, wasm
- tags: webassembly, wasi, component-model, cranelift, aot, bytecode-alliance, sandboxing, embeddable, jit, sandbox, linux, macos

## Member repositories
- bytecodealliance/wasmtime (main) score 95
- bytecodealliance/cranelift (mirror) score 10
- bytecodealliance/wizer (mirror) score 74

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:26.811568+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:02:00.836921+00:00, confidence not recorded.
  - readme: https://github.com/bytecodealliance/wasmtime (fetched 2026-08-28T04:11:26.811568+00:00, sha 6d16e78aff46)
  - homepage: https://wasmtime.dev/ (fetched 2026-08-29T08:00:02.219020+00:00, sha dca95fadf995)
  - site_page: https://docs.wasmtime.dev/ (fetched 2026-08-29T08:00:02.221941+00:00, sha 506c2e1994af)
  - registry_crates: https://crates.io/api/v1/crates/wizer (fetched 2026-08-29T08:00:02.223940+00:00, sha a6a3cfb1f42b)
- Data as of 2026-08-30T08:39:29.467469+00:00.