MIME type lookup
Look up the MIME type for a file extension such as json or webp, or find which extensions belong to a type like image/png.
- Runs in your browser
- No upload
- Result stays on your device
Privacy & limitsRuns in your browser. Nothing is uploaded.
Input content stays in this tab; Refentra does not upload or store it. Optional aggregate action counts are sent only with your usage consent. Clear the workspace when finished.
Supported profile: Curated IANA subset, checked 2026-10-07; extension lookup does not inspect file content or server headers.
Maximum text: 200,000 UTF-16 units; parser limits can be smaller. Worker time limit: 15 seconds (regex 1.5 seconds).
Check the input and the result
- Prepare and choose the operation
Enter a known extension or media type and check the matching entry from the curated list before you set a server header.
- Check a concrete example
Use this sample and compare the indicated result: json → application/json; application/json → json
- Check the output before you reuse it
Keep an extension hint separate from the actual Content-Type header. Either one can be wrong for what is in the file.
Answers for this task
Does lookup inspect a file?
No. No file sniffing takes place. A .jpg name alone doesn't prove the contents are JPEG or that an upload is safe.
What should I check if the input fails?
Try the extension without a path, or the media type itself. If nothing matches, the entry may be outside the curated subset.
Where does this tool stop?
The subset based on IANA was checked on 2026-10-07. It is not the complete registry and not a live content-type lookup service.