File Type Mismatch

How to use

1. Choose a file

   Select one file whose name or MIME type may be incorrect.

2. Compare three clues

   Review the extension, declared MIME, and format detected from the signature.

3. Investigate a mismatch

   Check the original source or generation process instead of blindly renaming the file.

Scope of the result

Polyglot files, damaged containers, formats inside ZIP files, and unsupported signatures cannot be fully identified. The result is an investigative clue, not proof of file identity.

Frequently asked questions

Will changing the extension fix every mismatch?

No. The Content-Type or file generation process may also be wrong. Use the result as evidence while checking the source.

Does unknown mean safe?

No. It means no supported signature was identified and says nothing about safety or validity.

Can this detect malware?

No. This tool only checks format mismatches and is not a security scanner.