Detect files where the extension lies about the content. Identifies double-extension malware risks instantly.
Free is enough for most one-off jobs. Pro raises the file and batch caps; Pro + Media unlocks GB-scale streaming and unlimited duration.
Larger files supported on Developer (5 GB CSV) and Enterprise (unlimited). All processing happens in your browser — files never reach a server.
Drop any file.
The tool reads the first 64 bytes and matches against known magic-byte signatures.
See the actual content type and whether it matches the file extension.
0 bytes uploaded. Magic Byte Validator runs entirely in your browser. Files, passwords, and PGP private keys never leave your device. No analytics fire during processing — only after you opt-in to dashboard audit logging.
Double-extension files (`photo.jpg.exe`) are a classic malware vector — magic-byte validation catches them.
300+ formats via the file-type library — images, archives, executables, documents, audio, video.