File Extensions JSON Dataset

A comprehensive reference of common file extensions with MIME types for file upload validation, icon assignment, and content type handling.

Quick Stats

• 35 file extensions covering common formats
• ~3 KB file size
• Fields: extension, type, mime_type, description

Download

• Download JSON
• Open in JSONLint

Schema

Field	Type	Description	Example
extension	string	Extension with dot	".json"
type	string	File category	"Data"
mime_type	string	MIME type	"application/json"
description	string	Full name	"JavaScript Object Notation"

File Types

• Data - JSON, XML, CSV, YAML
• Code - JS, TS, Python, Java, Go, Rust, etc.
• Web - HTML, CSS
• Image - PNG, JPG, GIF, SVG, WebP
• Audio - MP3, WAV
• Video - MP4
• Document - PDF, MD, TXT
• Archive - ZIP, TAR
• Database - SQL

Sample Data

{
  "extensions": [
    {
      "extension": ".json",
      "type": "Data",
      "mime_type": "application/json",
      "description": "JavaScript Object Notation"
    },
    {
      "extension": ".ts",
      "type": "Code",
      "mime_type": "text/typescript",
      "description": "TypeScript"
    },
    {
      "extension": ".png",
      "type": "Image",
      "mime_type": "image/png",
      "description": "Portable Network Graphics"
    }
  ]
}

Usage Examples

JavaScript - File Upload Validation

const response = await fetch('https://jsonlint.com/datasets/file-extensions.json');
const { extensions } = await response.json();

// Build allowed extensions for images
const imageExtensions = extensions
  .filter(e => e.type === 'Image')
  .map(e => e.extension);
// [".png", ".jpg", ".gif", ".svg", ".webp"]

// Validate file upload
function isValidImage(filename) {
  const ext = '.' + filename.split('.').pop().toLowerCase();
  return imageExtensions.includes(ext);
}

// Get MIME type for Content-Type header
function getMimeType(filename) {
  const ext = '.' + filename.split('.').pop().toLowerCase();
  const found = extensions.find(e => e.extension === ext);
  return found ? found.mime_type : 'application/octet-stream';
}

File Type Icon Assignment

const typeIcons = {
  'Code': 'code-icon',
  'Image': 'image-icon',
  'Data': 'data-icon',
  'Document': 'doc-icon',
  // ...
};

function getFileIcon(filename) {
  const ext = '.' + filename.split('.').pop().toLowerCase();
  const found = extensions.find(e => e.extension === ext);
  return found ? typeIcons[found.type] : 'file-icon';
}

Server-Side Content Types

// Express.js middleware
app.use((req, res, next) => {
  const ext = path.extname(req.path);
  const found = extensions.find(e => e.extension === ext);
  if (found) {
    res.type(found.mime_type);
  }
  next();
});

Use Cases

• File upload validation - Restrict uploads to specific file types
• MIME type detection - Set correct Content-Type headers
• File icons - Display appropriate icons for file types
• Syntax highlighting - Choose highlighter based on extension
• File browsers - Categorize and filter files

Related Datasets

• Programming Languages - More language details
• HTTP Status Codes - API response handling