Developer Reference
MIME Types Reference
MIME type reference: map file extensions to Content-Type headers. Free lookup for web, images, documents, audio, video, and fonts.
MIME types tell browsers and servers what file format they're handling. Developers need quick access to the correct Content-Type header value when serving files, configuring uploads, or setting cache rules. This reference maps common extensions to their standard MIME types across all major categories.
Text & web
| Extension | MIME type |
|---|---|
.html | text/html |
.css | text/css |
.js | text/javascript |
.json | application/json |
.xml | application/xml |
.csv | text/csv |
.txt | text/plain |
.md | text/markdown |
.svg | image/svg+xml |
Images
| Extension | MIME type |
|---|---|
.png | image/png |
.jpg / .jpeg | image/jpeg |
.gif | image/gif |
.webp | image/webp |
.avif | image/avif |
.ico | image/x-icon |
.bmp | image/bmp |
.tiff | image/tiff |
Documents, audio, video, archives
| Extension | MIME type |
|---|---|
.pdf | application/pdf |
.zip | application/zip |
.gz | application/gzip |
.doc | application/msword |
.docx | application/vnd.openxmlformats-officedocument.wordprocessingml.document |
.xls | application/vnd.ms-excel |
.mp3 | audio/mpeg |
.wav | audio/wav |
.mp4 | video/mp4 |
.webm | video/webm |
.woff2 | font/woff2 |
How this reference is used
- Setting the correct Content-Type header when uploading files to a server or API
- Configuring a web server or CDN to serve files with the right MIME type
- Validating user uploads by checking file extensions against expected MIME types
- Debugging browser issues where a resource fails to load due to incorrect Content-Type
- Building a file upload form that restricts accepted file types
Frequently asked questions
Why does Content-Type matter?
Browsers use Content-Type to decide how to handle a file—whether to render it, download it, or block it. Wrong headers can break file downloads, prevent images from displaying, or trigger security errors. Servers also use it to apply appropriate caching rules.
What's the difference between a MIME type and a file extension?
A file extension (.jpg, .pdf) is just a label on the filename. MIME type (image/jpeg, application/pdf) is the actual metadata sent in HTTP headers that tells the browser what the content really is. They should match, but a file can have any extension.
Do I need to memorize these?
No. Keep this reference bookmarked. The most common ones (text/html, application/json, image/png) you'll learn naturally, but for obscure formats or when setting up servers, a quick lookup saves time and prevents bugs.