How to use this developer tool
- Enter extensions, filenames, or MIME values one per line.
- Select JSON or CSV output.
- Run the lookup.
- Review representative mappings and unknown fallbacks.
#067 · Developer Utilities Developer Tool
MIME Type Lookup
Look up common MIME mappings from extensions, filenames, or MIME values using a built-in browser-side database.
Developer Input
Extensions, filenames, or MIME valuesLookup Table
Representative mappings| Input | MIME Type | Category |
|---|
What this developer tool does
Normalizes file extensions, checks compound extensions first, and returns a representative MIME record.
Classify input → normalize extension → prefer compound match → look up built-in map → emit metadata or fallback.
Server and operating-system mappings can differ; the output provides common web defaults.
Example
index.html data.json archive.tar.gz application/pdf
Tips for better output
- Send unknown binary files as application/octet-stream.
- Set text charsets separately when appropriate.
- Check compound extensions before the last suffix only.
FAQ
What MIME type should I use for a JSON file?
The common MIME type is application/json.
How do I find a MIME type from a filename extension?
Enter the filename or extension and run the lookup.
Which file extensions use application/octet-stream?
Unknown or generic binary extensions commonly fall back to application/octet-stream.
What is the correct MIME type for SVG, WebP, and AVIF?
Common values are image/svg+xml, image/webp, and image/avif.
How do I look up MIME types for multiple files at once?
Enter one filename or extension per line and export the batch result.
Related developer tools
Supported formats and output
Extensions, filenames, and MIME values. Output is JSON or CSV.