File Type Detection
Read a file signature and see what the file really is, regardless of its extension.
Files & batch Client-side Magic number table
Tool preview
How to use it
- 01
Drop a file.
- 02
Compare the declared type with the detected one.
Limitations
- ! It reads the first bytes only, so a file with a valid header but corrupted body still shows as valid.
- ! Archives and container formats report their container type, not the contents.
FAQ
Why would a file be disguised?
Malware is often shipped as a document-looking extension while the header is an executable.
Can it repair a wrong extension?
No, it only reports the mismatch.
Is the file uploaded?
No, only the header bytes are read locally.
Files never leave your device
Processing happens in your browser using the File API, WebAssembly and Web Workers. There is no upload endpoint.
Technical details
- Processing
- Client-side
- Implementation
- Magic number table
- Category
- Files & batch
- Network requests
- None while processing