The simplest web framework and site generator yet.
Let nothing get between you and the high-performance engine that is a modern browser.
- Minimal yet powerful: a router, and a few composable functions to return Responses.
- It all works the same: static site generation, server rendering HTML, or even JSON.
- Multi-runtime: works on Deno, Node.js, Bun and Workers.
- No bloat: written in just ~700 lines of TypeScript, Mastro is a tiny library.
- No client-side JavaScript (until you add some): create MPA websites that load fast.
- No bundler (until you add one): your code ships exactly as you wrote it.
- No magic: use plain
<img>and<a>tags referencing HTTP-first assets. - No VC-money: no eventual enshitification – selling is none of our business.
- No update treadmill: we use web standards instead of complex dependencies.
- No lock-in: swap out Mastro or fork it – it’s only ~700 lines after all.
