---
title: Upload files via HTTP using FormData
sidebarTitle: Upload files via HTTP using FormData
mode: center
---
To upload files via HTTP with Bun, use the [`FormData`](https://developer.mozilla.org/en-US/docs/Web/API/FormData) API. Let's start with a HTTP server that serves a simple HTML web form.
```ts index.ts icon="/icons/typescript.svg"
const server = Bun.serve({
port: 4000,
async fetch(req) {
const url = new URL(req.url);
// return index.html for root path
if (url.pathname === "/")
return new Response(Bun.file("index.html"), {
headers: {
"Content-Type": "text/html",
},
});
return new Response("Not Found", { status: 404 });
},
});
console.log(`Listening on http://localhost:${server.port}`);
```
---
We can define our HTML form in another file, `index.html`.
```html index.html icon="file-code"
Form
```
---
At this point, we can run the server and visit [`localhost:4000`](http://localhost:4000) to see our form.
```bash
bun run index.ts
Listening on http://localhost:4000
```
---
Our form will send a `POST` request to the `/action` endpoint with the form data. Let's handle that request in our server.
First we use the [`.formData()`](https://developer.mozilla.org/en-US/docs/Web/API/Request/formData) method on the incoming `Request` to asynchronously parse its contents to a `FormData` instance. Then we can use the [`.get()`](https://developer.mozilla.org/en-US/docs/Web/API/FormData/get) method to extract the value of the `name` and `profilePicture` fields. Here `name` corresponds to a `string` and `profilePicture` is a `Blob`.
Finally, we write the `Blob` to disk using [`Bun.write()`](/docs/runtime/file-io#writing-files-bun-write).
{/* prettier-ignore */}
```ts index.ts icon="/icons/typescript.svg"
const server = Bun.serve({
port: 4000,
async fetch(req) {
const url = new URL(req.url);
// return index.html for root path
if (url.pathname === "/")
return new Response(Bun.file("index.html"), {
headers: {
"Content-Type": "text/html",
},
});
// parse formdata at /action // [!code ++]
if (url.pathname === "/action") { // [!code ++]
const formdata = await req.formData(); // [!code ++]
const name = formdata.get("name"); // [!code ++]
const profilePicture = formdata.get("profilePicture"); // [!code ++]
if (!profilePicture) throw new Error("Must upload a profile picture."); // [!code ++]
// write profilePicture to disk // [!code ++]
await Bun.write("profilePicture.png", profilePicture); // [!code ++]
return new Response("Success"); // [!code ++]
} // [!code ++]
return new Response("Not Found", { status: 404 });
},
});
```