MIME Type Lookup
Runs in your browser — your data is never uploaded.
Look up the Content-Type a file should be served with, or go the other way from a type to its extensions. Serving the wrong one is not cosmetic: with the nosniff header that every security guide tells you to set, a stylesheet sent as text/plain is refused outright and a module sent as anything but a JavaScript type throws a MIME checking error, with nothing in it to suggest the file is fine.
0 characters · runs entirely in your browser
How to use MIME Type Lookup
- 1
Enter one or more file extensions, filenames, or MIME types — one per line.
- 2
Read the mapping, with a note wherever the obvious answer is wrong.
- 3
Copy the result into your server config or upload validation.
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Frequently asked questions
What is the correct MIME type for JavaScript?+
text/javascript. The WHATWG specification settled on it, and application/javascript — long considered the correct one — is now obsolete though still accepted everywhere. What is not accepted is text/plain: with nosniff set, an ES module served that way is refused and the page fails with a strict MIME type error.
Is image/jpg a real MIME type?+
No. The registered type is image/jpeg, whatever the file extension says. image/jpg appears constantly in hand-written config and upload filters, and a validator checking for it rejects every genuine JPEG a browser sends.
Why does my SVG not display?+
Usually because it is served as image/svg rather than image/svg+xml. The suffix is part of the type, not decoration — it tells the browser the payload is XML. Without it, an otherwise perfect SVG renders as nothing.
What does application/octet-stream do?+
It means “arbitrary bytes”, and browsers respond by downloading rather than displaying. It is the correct fallback for a type you do not recognise, and the wrong answer for anything you want rendered — a PDF served this way downloads instead of opening in the viewer.
Should I add charset to the type?+
For text types, yes — text/html; charset=utf-8 removes any ambiguity about decoding. For JSON, no: the format is defined as UTF-8 and the charset parameter is not registered for it, so adding one is at best ignored.