Host a WASM file and serve it from a URL
Put a WebAssembly module at a stable address that a page can fetch and instantiate — served with the right content type.
Drop your WASM module here
Any other file works too — up to 25.0 MB, or 100.0 MB for a whole site
Free to use. Your WASM file is live at your-name.99helpers.site in about ten seconds.
What is a .wasm file?
WebAssembly is a binary instruction format that runs in browsers at near-native speed. Code written in Rust, C++, Go or AssemblyScript compiles to a .wasm module, which JavaScript loads and calls — it's how heavy computation, games and ported desktop software run on the web.
What people use WASM files for
- Compiled Rust, C++ or Go running in a browser
- Image, video and audio processing in the client
- Games and simulations ported to the web
- Cryptography and computation too slow in JavaScript
What opens a WASM file
- Every modern browser
- Node.js and Deno
- wasm-pack, Emscripten and TinyGo, for compiling
- Wasmtime and Wasmer, outside the browser
How to host a WASM file
- 1
Drop your WASM file in
Drag it onto the box at the top of this page, or click to choose it. Files up to 25 MB are supported, and nothing is uploaded until you publish.
- 2
Pick an address
Type a name and we'll tell you straight away whether it's free. That becomes the link: app-module.99helpers.site
- 3
Publish and share
Create a free account — that step exists so the file is yours to update, replace or delete — and the link is live within seconds.
The same three steps work for any file — see how file hosting works on 99helpers.com.
What happens when someone opens the link
Opening the link downloads the binary — there's nothing to display. Fetched by a page, it instantiates and runs, which works because we serve it as application/wasm.
Why host a WASM file instead of emailing it?
Instantiating a module efficiently requires the correct content type, which many static hosts get wrong. Hosting here serves it as application/wasm, so instantiateStreaming works rather than falling back to the slower path.
Worth knowing before you publish
- WebAssembly.instantiateStreaming needs the application/wasm content type, which is what we serve — that's the common reason it fails elsewhere.
- Cross-origin fetches are subject to CORS, so a module hosted here may not be loadable by JavaScript on another domain.
- Modules are often large; wasm-opt usually shrinks them substantially.
WASM hosting questions
- Is it served with the right content type?
- Yes, application/wasm — which is what WebAssembly.instantiateStreaming requires. Getting that wrong is the usual reason streaming instantiation fails on other static hosts.
- Can my website fetch this module?
- That depends on CORS. Browser JavaScript on another domain may be blocked, since a hosted file doesn't send permissive cross-origin headers. Hosting the module alongside the page that uses it avoids the problem entirely.
- Can I host the whole app here?
- Yes — upload the HTML, JavaScript and .wasm together as a folder and it publishes as a site, with everything at the same origin so there's no CORS issue.
Put your WASM file online now
It takes about ten seconds, and you only make an account once the file is ready to go live.
Hosting guides for related formats
WASM is one of over 211 formats you can host — see free file hosting for any file type for the full list, or read the hosting guides for other file types.