MIME Type Lookup
Paste a file name or an extension and get the MIME type, its category, what the format actually is, the extensions it gets confused with, and what Furtu can do with it. The table ships inside the page, so the lookup works offline and a file name never leaves the tab.
Auto handles both, and a leading dot is optional.
How mime type lookup works
- Paste a file name or a typeSeveral lines at once, up to twenty, and each is looked up separately.
- Read the entryType, category, what the format is, and the extensions it is confused with.
- Check the neighboursThe confusion list is usually the useful part when a type is not what you expected.
What you get
Find the MIME type behind a file extension, and what it means. Everything happens inside this page: the file is read by your browser, transformed in memory and handed straight back to you as a download. There is no upload queue, no waiting for a server, and nothing left behind when you close the tab.
Supported formats
This tool works on text you paste or type, so there is no file format to worry about. Nothing you type is sent anywhere.
Limitations, stated up front
- The table covers the formats that matter in practice, not every registered type. A miss is reported plainly rather than guessed at.
- Only the name is read. Nothing is opened, inspected or identified by its contents.
Frequently asked questions
Why does a PNG sometimes arrive as plain text?
Because the type comes from two places and they can disagree. The browser guesses from the extension; a server announces what it believes the file is in the content-type header, and that is what wins. A misconfigured upload endpoint serving a PNG as plain text is common, and it is why a download can produce a file that will not open until it is renamed.
Is there one official list?
There is an IANA registry, and it is smaller than most people expect. Everything else is convention: the MDN list, the widely copied server configuration, and the platform-specific tables that disagree with each other. Which is why a miss in Furtu’s table is normal rather than an error, and why the tool says so.
Why is plain text the right type for a script file?
Because the old application/javascript type was never registered, so browsers and CDNs sent it anyway and the standard was eventually fixed to the text one. Most of the ecosystem ignores the difference, and some older applications still insist on the old one.
Can it identify a file by its contents?
No, and it is worth being clear about that. This reads the name you paste. Identifying a file by its magic bytes is a different job; the tools that accept uploads do that as they read them.