Category: Multipart

multipart/form-data

multipart/form-data is used in HTTP POST requests when submitting HTML forms containing file uploads (`<input type="file">`). Each form field is separated by a unique boundary delimiter string.

MIME / CONTENT-TYPE

multipart/form-data

ASSOCIATED EXTENSIONS

None / Stream

PRIMARY CATEGORY

Multipart

HTTP Headers & Web Server Configurations

Standard HTTP Response Header
Content-Type: multipart/form-data; boundary=---------------------------974767299852498929531610575

Send this exact header in HTTP responses to instruct browsers how to decode and render the payload.

Node.js / Express / Web API
<form action="/api/upload" method="POST" enctype="multipart/form-data"> <input type="file" name="avatar"> <button type="submit">Upload</button> </form>
NGINX Configuration (mime.types)
client_max_body_size 50M;
Apache (.htaccess / httpd.conf)
LimitRequestBody 52428800

Security Advisory & Hardening

Limit maximum request body size (`client_max_body_size`) and strictly validate MIME type and magic bytes on server-side to prevent malicious file execution.

Frequently Asked Questions

multipart/form-data Questions & Answers

Common questions regarding MIME types, Content-Type headers, and web server configurations.

The standard HTTP response header is: "Content-Type: multipart/form-data; boundary=---------------------------974767299852498929531610575".