What is a MIME type and why is it important?

A MIME type (Multipurpose Internet Mail Extensions type) is a standard way of classifying file types on the internet. It tells browsers, servers, and applications how to handle different files. MIME types follow the format 'type/subtype', like 'image/png' for PNG images or 'application/pdf' for PDF documents. They're important because they determine how browsers display content (inline vs download), enable proper file validation in uploads, ensure correct handling in email attachments, help APIs communicate data formats, and allow servers to set proper Content-Type headers. Without correct MIME types, files might not display properly, security vulnerabilities could arise, and file downloads might fail. Every HTTP response should include a Content-Type header with the appropriate MIME type.

How do I use MIME types in my web application?

MIME types are primarily used in HTTP headers to tell browsers and clients how to handle files. In server responses, set the Content-Type header: 'Content-Type: image/png' for images or 'Content-Type: application/json' for JSON APIs. For file uploads, validate the MIME type on both client and server sides. In HTML, use the accept attribute: ' ' to restrict file types. In JavaScript, check file.type property to validate uploads. For APIs, use Content-Type to specify request/response formats. Common examples: serve images with 'image/jpeg', return JSON with 'application/json', stream video with 'video/mp4', and serve fonts with 'font/woff2'. Always validate MIME types server-side for security.

Why is my file downloading instead of displaying in the browser?

Files download instead of displaying when the server sends the wrong MIME type or includes a Content-Disposition: attachment header. Browsers can display certain file types inline (images, PDFs, text, video) if the correct MIME type is set. If you send 'application/octet-stream' (generic binary), the browser will download it. To fix this, ensure your server sends the correct Content-Type header matching the file extension. For images, use 'image/png' or 'image/jpeg'. For PDFs, use 'application/pdf'. For videos, use 'video/mp4'. Also check that you're not setting 'Content-Disposition: attachment' which forces downloads. Use 'Content-Disposition: inline' to display files in the browser. Check your server configuration (.htaccess for Apache, mime.types for Nginx) to ensure proper MIME type mappings.

What is the difference between content type and MIME type?

MIME type and content type are essentially the same thing in web development. 'MIME type' is the original standard name (Multipurpose Internet Mail Extensions), while 'content type' is the HTTP header name that carries the MIME type value. When you see 'Content-Type: image/png' in HTTP headers, 'Content-Type' is the header name and 'image/png' is the MIME type. The terms are used interchangeably because the Content-Type header's value is always a MIME type. Historically, MIME types were developed for email attachments but were adopted by HTTP for web content. In practice, developers say 'set the content type' or 'check the MIME type' to mean the same thing. Both refer to the type/subtype format like 'text/html', 'application/json', or 'video/mp4'.

How can I validate file uploads using MIME types?

File upload validation using MIME types requires both client-side and server-side checks. On the client (HTML/JavaScript), use the accept attribute: ' ' to filter file picker. In JavaScript, check the file.type property: 'if (file.type === "image/png") { ... }'. However, client-side validation alone is insecure because it can be bypassed. Always validate server-side by checking the Content-Type header and inspecting actual file content (magic numbers/file signatures). Don't trust the MIME type sent by the client - malicious users can fake it. Use libraries to verify file content matches the claimed type. For example, check that a file claiming to be 'image/jpeg' actually starts with JPEG magic bytes (FF D8 FF). Combine MIME type checking with file extension validation and content inspection for robust security.

📄

MIME Type Finder

Find MIME type for file extensions instantly. Look up media types for images, videos, documents, and more.

Developer Tools

Loading tool...

How to Use MIME Type Finder

MIME Type Finder is a quick and easy tool for looking up MIME types (media types) for any file extension. Whether you're configuring web servers, building applications, or writing HTTP headers, this tool provides instant access to MIME type information.

Quick Start Guide

Enter Extension: Type any file extension in the search box (e.g., .png, .pdf, or just png)
View Results: Instantly see the MIME type, category, and description
Copy MIME Type: Click "Copy MIME Type" to copy for use in your code
Explore Examples: Click example buttons to see common file types

Understanding MIME Types

What is a MIME Type?

MIME (Multipurpose Internet Mail Extensions) types are standard labels used to identify file types on the internet. They tell browsers and servers how to handle different files.

Format: type/subtype

Examples:

image/png - PNG image
application/pdf - PDF document
video/mp4 - MP4 video

Why MIME Types Matter:

Web Development: Serve files with correct Content-Type headers
File Uploads: Validate file types on servers
APIs: Specify response and request formats
Email: Attach files with proper MIME types
Browser Handling: Determine how browsers open files

Common Use Cases

1. Setting HTTP Headers

Problem: Need to serve a PNG image with correct headers

Solution:

Extension: .png
MIME Type: image/png

HTTP Header:
Content-Type: image/png

2. File Upload Validation

Problem: Validate PDF uploads in web forms

Solution:

Extension: .pdf
MIME Type: application/pdf

JavaScript validation:
if (file.type === 'application/pdf') {
  // Valid PDF
}

3. API Response Types

Problem: Return JSON data from API

Solution:

Extension: .json
MIME Type: application/json

Response Header:
Content-Type: application/json

4. Video Streaming

Problem: Stream MP4 video on website

Solution:

Extension: .mp4
MIME Type: video/mp4

HTML5 video:
<video>
  <source src="video.mp4" type="video/mp4">
</video>

5. Font Loading

Problem: Load web fonts correctly

Solution:

Extension: .woff2
MIME Type: font/woff2

CSS:
@font-face {
  src: url('font.woff2') format('woff2');
}

6. Document Downloads

Problem: Force download of Word document

Solution:

Extension: .docx
MIME Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document

HTTP Header:
Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
Content-Disposition: attachment; filename="document.docx"

Supported File Types

Images:

.jpg, .jpeg - image/jpeg
.png - image/png
.gif - image/gif
.webp - image/webp
.svg - image/svg+xml
.ico - image/x-icon
.bmp - image/bmp
.tiff - image/tiff
.avif - image/avif

Videos:

.mp4 - video/mp4
.webm - video/webm
.avi - video/x-msvideo
.mov - video/quicktime
.mkv - video/x-matroska
.mpeg - video/mpeg

Audio:

.mp3 - audio/mpeg
.wav - audio/wav
.ogg - audio/ogg
.m4a - audio/mp4
.flac - audio/flac
.aac - audio/aac

Documents:

.pdf - application/pdf
.doc - application/msword
.docx - application/vnd.openxmlformats-officedocument.wordprocessingml.document
.xls - application/vnd.ms-excel
.xlsx - application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.ppt - application/vnd.ms-powerpoint
.pptx - application/vnd.openxmlformats-officedocument.presentationml.presentation
.txt - text/plain
.csv - text/csv

Web:

.html - text/html
.css - text/css
.js - text/javascript
.json - application/json
.xml - application/xml

Archives:

.zip - application/zip
.rar - application/vnd.rar
.7z - application/x-7z-compressed
.tar - application/x-tar
.gz - application/gzip

Fonts:

.woff - font/woff
.woff2 - font/woff2
.ttf - font/ttf
.otf - font/otf
.eot - application/vnd.ms-fontobject

Technical Details

MIME Type Structure:

type/subtype

Main Types:

text - Text documents (HTML, CSS, plain text)
image - Images (PNG, JPEG, GIF)
audio - Audio files (MP3, WAV)
video - Video files (MP4, WebM)
application - Application data (PDF, JSON, ZIP)
font - Font files (WOFF, TTF)

Common Subtypes:

plain - Plain text
html - HTML documents
json - JSON data
pdf - PDF documents
zip - ZIP archives
octet-stream - Generic binary data

Special MIME Types:

application/octet-stream - Generic binary, forces download
multipart/form-data - Form uploads with files
text/plain; charset=utf-8 - Text with character encoding

Best Practices

Server Configuration:

Always set correct MIME types in server responses:

Apache (.htaccess):

AddType image/webp .webp
AddType font/woff2 .woff2
AddType application/json .json

Nginx:

types {
    image/webp webp;
    font/woff2 woff2;
    application/json json;
}

Node.js/Express:

res.setHeader('Content-Type', 'image/png')

File Upload Validation:

Validate MIME types on both client and server:

HTML:

<input type="file" accept="image/png,image/jpeg">

JavaScript:

const allowedTypes = ['image/png', 'image/jpeg']
if (!allowedTypes.includes(file.type)) {
  alert('Invalid file type')
}

Security Considerations:

Never trust client-provided MIME types alone
Validate file content, not just extension
Use server-side validation for uploads
Set proper Content-Security-Policy headers

Common MIME Type Scenarios

Scenario 1: Image Gallery

You need MIME types for:

Thumbnails: image/webp or image/jpeg
High-res: image/png
Icons: image/svg+xml

Scenario 2: Document Management

You need MIME types for:

PDFs: application/pdf
Word docs: application/vnd.openxmlformats-officedocument.wordprocessingml.document
Spreadsheets: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

Scenario 3: Media Streaming

You need MIME types for:

Video: video/mp4, video/webm
Audio: audio/mpeg, audio/ogg
Subtitles: text/vtt

Scenario 4: API Development

You need MIME types for:

JSON responses: application/json
XML responses: application/xml
Binary data: application/octet-stream

Troubleshooting

Issue: Browser not displaying file correctly

Solution: Check the Content-Type header matches the actual file type. Use browser DevTools Network tab to inspect headers.

Issue: File downloads instead of displaying

Solution: Use correct MIME type (not application/octet-stream). Example: Use image/png for PNG images, not generic binary type.

Issue: Font not loading

Solution: Ensure correct MIME type for font format. WOFF2 needs font/woff2, not application/octet-stream.

Issue: Video not playing

Solution: Check browser support for format and ensure correct MIME type. Use video/mp4 for MP4, video/webm for WebM.

Issue: File upload validation failing

Solution: Some browsers report different MIME types. Validate file extension and content, not just MIME type.

Browser Compatibility

This tool works in all modern browsers:

✅ Chrome/Edge (latest)
✅ Firefox (latest)
✅ Safari (latest)
✅ Opera (latest)

Required Features:

JavaScript enabled
Clipboard API (for copy functionality)

Privacy & Security

Client-Side Processing:

All MIME type lookups happen entirely in your browser. Your searches:

Never leave your device
Are not sent to any server
Are not logged or stored
Disappear when you close/refresh the page

Safe for Sensitive Projects:

You can safely look up MIME types for:

Proprietary file formats
Internal project files
Any file extensions

Advanced Use Cases

Custom File Types:

Create custom MIME types for proprietary formats:

application/vnd.company.product+json

Multi-Part Content:

Handle complex uploads:

multipart/form-data
multipart/mixed

Content Negotiation:

Support multiple formats:

Accept: application/json, application/xml

Email Attachments:

Attach files with correct MIME types:

Content-Type: application/pdf
Content-Disposition: attachment; filename="report.pdf"

MIME Type Categories

Text Files:

Plain text, HTML, CSS, JavaScript, CSV, XML

Images:

Raster (JPEG, PNG, GIF) and Vector (SVG)

Audio/Video:

Streaming formats, compressed/uncompressed

Documents:

Office files, PDFs, eBooks

Archives:

Compressed files and packages

Fonts:

Web fonts and system fonts

Applications:

Executables, packages, binary data

Tips & Tricks

Use Examples: Click example buttons to see common file types
Omit the Dot: Works with or without leading dot (.png or png)
Copy Quickly: Use "Copy MIME Type" for instant clipboard copy
Bookmark Tool: Quick reference for web development
Check Headers: Use browser DevTools to verify MIME types
Validate Uploads: Always check MIME types server-side
Modern Formats: Consider newer formats like WebP and WOFF2
Test Compatibility: Check browser support for MIME types

Frequently Asked Questions

Related Development Tools

{ }

JSON Formatter & Validator

Featured

Format, validate, and pretty-print JSON with our developer-friendly editor.

Use Tool →

📱

QR Code Generator

Featured

Create custom QR codes for URLs, text, and contact info

Use Tool →

{}

CSS Beautifier

Format messy CSS into clean, readable styles with consistent indentation and spacing. Perfect for cleaning up minified or poorly formatted stylesheets.

Use Tool →

🔄

CSV Sorter

Sort CSV by columns - Order CSV rows by one or more columns in ascending or descending order with multi-level sorting support

Use Tool →

🔄

TSV to CSV Converter

Convert TSV to CSV - Transform tab-separated values to comma-separated values with automatic quoting

Use Tool →

🔄

CSV to TSV Converter

Convert CSV to TSV - Transform comma-separated values to tab-separated values with automatic quote removal

Use Tool →

✏️

CSV Column Renamer

Rename CSV columns - Change CSV column headers and standardize naming conventions with camelCase, snake_case, or Title Case

Use Tool →

🌐

HTTP Status Code Checker

Look up HTTP status codes and their meanings instantly. Understand error codes and how to fix them.

Use Tool →

Share Your Feedback

Help us improve this tool by sharing your experience