What is MIME Type?

MIME Type is a standardized identifier used to indicate the nature and format of a file or data, consisting of a type and subtype separated by a slash, enabling proper handling of content across the internet.

Quick Facts

Full NameMultipurpose Internet Mail Extensions Type
Created2026-02-01
SpecificationOfficial Specification

How MIME Type Works

MIME types, originally developed for email attachments, have become the standard way to identify content types on the web. Each MIME type consists of a type (e.g., text, image, application) and a subtype (e.g., html, png, json), optionally followed by parameters. Web servers send MIME types in Content-Type headers to tell browsers how to handle responses. Common examples include 'text/html' for web pages, 'application/json' for JSON data, and 'image/png' for PNG images. The Internet Assigned Numbers Authority (IANA) maintains the official registry of MIME types.

Key Characteristics

  • Format: type/subtype (e.g., text/plain, image/jpeg)
  • Optional parameters (e.g., text/html; charset=utf-8)
  • Registered types: text, image, audio, video, application, multipart, message
  • Vendor-specific types use 'vnd.' prefix
  • Unregistered types use 'x-' prefix (deprecated)
  • Case-insensitive by specification
  • Critical for proper content handling

Common Use Cases

  1. HTTP Content-Type headers
  2. File upload validation
  3. Email attachment handling
  4. API response formatting
  5. Browser content rendering decisions

Example

Content-Type: application/json; charset=utf-8

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