MIME type lookup · Guide
MIME Types for File Uploads
Uploads rely on MIME types for validation, but they are only part of a safe check. Here is how to use them well.
Validate the declared type
Checking the uploaded file’s MIME type against an allow-list is a sensible first gate, rejecting obviously wrong formats early.
Do not trust it alone
A client can lie about the MIME type, so combine it with extension checks and server-side content inspection for anything security-sensitive.
Frequently asked questions
Can I use this for production work?
Yes, for inspection, formatting and quick generation. Still review the output before committing it to production code or configuration.
Ready to try it?
Open the free browser-based MIME type lookup and apply what you just read — no sign-up, runs locally.
Open the MIME type lookup tool