MIME Type Checker

Detect MIME types from file extension or magic bytes — files read locally, never uploaded.

100% In-Browser & Private — your data never leaves this device
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How to use the MIME Type Checker

  1. Enter a filename to lookup by extension.
  2. Or drop a file to sniff magic bytes from the first bytes.
  3. Review the detected MIME type and source.

FAQ

Is the whole file uploaded?
No. Only the filename or first ~16 bytes are read in-browser.

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