MIME Multipart Builder

Build a raw multipart/form-data request body and Content-Type header from field name/value pairs.

Your file is processed locally in your browser and is not uploaded to our server.

Boundary

Field name

Value

Content-Type header

Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW

Request body

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="username"

alice
------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="email"

alice@example.com
------WebKitFormBoundary7MA4YWxkTrZu0gW--

How to use MIME Multipart Builder

1Set a boundary string (or use the default).
2Add field name/value pairs.
3Copy the generated Content-Type header and raw multipart body.

Frequently asked questions

It is the standard encoding for HTML form submissions that include file uploads, and is commonly needed when manually constructing HTTP requests for testing.