MIME Type Detector

The MIME Type Detector inspects a file’s content signature to report its true MIME type, rather than trusting the extension, along with the category and a preview where possible. It is for developers verifying uploads and diagnosing files with wrong or missing extensions.

Extensions lie, and trusting them is a security and debugging hazard. Reading the actual byte signature locally reveals what a file really is, without uploading it anywhere.

1. Drop a file onto the tool.
2. Its leading bytes are read to identify the format signature.
3. The detected MIME type and category are shown.
4. A preview appears where the type supports it.
5. Use the result to confirm or correct the file’s handling.

• Content-signature detection
• MIME type and category reporting
• Preview where supported
• File never uploaded

• Verifying an uploaded file matches its claimed type
• Identifying a file with a missing or wrong extension
• Debugging why a server rejects a file as the wrong type
• Confirming a download is the format you expected

• Validate uploads by content signature on the server too; client-side checks can be bypassed.
• Some formats share signatures or are containers, so treat the result as the container type.
• A correct MIME type does not mean a file is safe — scan untrusted uploads separately.