MIME Type Lookup — File Extensions & Content-Type Reference

What Are MIME Types and Why Do They Matter?

MIME (Multipurpose Internet Mail Extensions) types tell browsers, servers, and APIs what kind of data is being transferred. Without the correct MIME type, a browser might render a file as plain text instead of executing it as JavaScript, or prompt a download instead of displaying an image inline.

Where MIME types appear

HTTP Content-Type header — Every HTTP response should declare the MIME type of its body. Content-Type: application/json; charset=utf-8
HTML <link> and <script> tags — The type attribute (though often optional in modern HTML5).
HTML forms — The enctype attribute for file uploads uses multipart/form-data.
Email attachments — Email clients use MIME types to decide how to display attachments.
Web server config — Nginx and Apache map file extensions to MIME types for static file serving.

Nginx MIME type configuration example

In nginx.conf, MIME types are declared in a types block inside http:

Config line	What it does
`text/html html htm;`	Serve `.html` files with `Content-Type: text/html`
`application/json json;`	Serve `.json` files as JSON
`font/woff2 woff2;`	Serve WOFF2 fonts with the correct type for browser caching
`include mime.types;`	Load Nginx's built-in MIME type map (covers most common types)