ToolZeno

MIME Type Lookup

Instant search, browse, compare, and analyze MIME (Media) types, file extensions, Content-Type HTTP headers, browser handling rules, and security notes.

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Export & Quick Actions

applicationIANA Registered
RFC Specification

application/json

JSON (JavaScript Object Notation)

Lightweight, human-readable data interchange format widely used in REST APIs, configuration files, and Web APIs.

Primary Extension:.jsonAlternatives:.map

Browser Support & Handling

Browsers display JSON inline formatted or raw, depending on built-in dev tools or extensions.

Inline RenderingSupported
Script ExecutionSafe (No JS)

Standard HTTP Headers

Content-Type

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

Accept

Accept: application/json

Multi-Language HTTP Snippets

curl -i -X GET \
  -H "Accept: application/json" \
  -H "Content-Type: application/json; charset=utf-8" \
  https://api.example.com/resource

Security Notes & Best Practices

JSON Hijacking & Content Sniffing

medium risk

Vulnerable to cross-site script injection if returned with text/html or without anti-sniffing headers.

Recommendation: Always set Content-Type: application/json; charset=utf-8 and X-Content-Type-Options: nosniff header.

Real-World Use Cases

  • 1RESTful API responses & payloads
  • 2Software config files (package.json, tsconfig.json)
  • 3NoSQL document storage

Related MIME Types

Mastering MIME (Media) Types & HTTP Content Negotiation

Multipurpose Internet Mail Extensions (MIME), standardized by IANA as Media Types, form the backbone of content exchange across the internet. Whenever a web server delivers an asset, API payload, or file upload to a browser or client SDK, it sends a Content-Type HTTP header that dictates how the browser must handle, render, or download the resource.

Whether you are building REST APIs, constructing cURL requests, configuring CORS headers, or sanitizing user file uploads, having an instant, offline-capable MIME type reference is essential.

Structure of a MIME Type

type / subtype + suffix ; parameter=value
Primary Type

Broad media category: application, image, text, audio, video, font, model, multipart, message.

Subtype & Suffix

Specific format identifier (e.g. json, png) and optional structured syntax suffix (e.g. +xml in image/svg+xml or +json in application/ld+json).

Parameters

Optional modifiers such as text character set (charset=utf-8) or multipart stream boundaries (boundary=---).

MIME Security & Upload Protection Rules

1. Enforce X-Content-Type-Options: nosniff: Always include this header on server responses to instruct browsers never to ignore the Content-Type header and execute guessed script payloads.

2. Validate Magic Bytes (File Signatures): Never rely solely on user-supplied file extensions or Content-Type headers during file uploads. Inspect the initial binary bytes (magic number) on the server.

3. Sanitize User SVGs & HTML: Vector formats like image/svg+xml and text/html can execute inline JavaScript. Use DOMPurify or render SVGs strictly via <img> tags.

100% Client-Side Privacy Guarantee

ToolZeno performs all MIME type search, category filtering, header code snippet generation, and comparison computations locally inside your browser sandbox. Zero search queries or file metadata are ever transmitted to any backend server.

Frequently Asked Questions

A MIME type (Multipurpose Internet Mail Extensions), also known as a Media Type, is a standardized 2-part string identifier used by internet protocols and web browsers to declare the format and nature of a document or file stream (e.g., application/json or image/png).

A file extension (such as .json or .png) is a operating system naming convention appended to a filename. A MIME type is an authoritative HTTP header sent by web servers over network protocols (Content-Type header) instructing client browsers how to process and render payload bytes regardless of file extension.

The Content-Type header informs the receiver about the MIME type of the HTTP body payload being sent in the current request or response. The Accept header is sent by clients in HTTP requests to negotiate which MIME format the client expects or prefers back from the server (Content Negotiation).

MIME Sniffing is a browser behavior where the browser inspects the actual byte stream of a response to determine its format if the server omits or sends an incorrect Content-Type header. If an attacker uploads a malicious script disguised as an image, MIME sniffing can execute XSS scripts. Serving the X-Content-Type-Options: nosniff header prevents browser sniffing.

No. The ToolZeno MIME Type Lookup operates 100% client-side inside your web browser. All dataset search matching, category filtering, HTTP snippet generation, and comparison matrices execute locally in browser memory without network transmissions.

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