Reveal the true format of any file using binary magic number signatures — not just the extension. Even a disguised .exe renamed to .jpg will be exposed instantly.
Need to check file type online without installing software? This free file type detector reads the binary magic number at the start of any file to reveal its true format — not just its extension. Drop any file to instantly get the MIME type, confidence score, SHA-256 checksum and a complete risk assessment. Everything runs in your browser — your files are never uploaded.
A file type detector identifies the real file format by reading the first few bytes of a file — known as the "magic number" or file signature. Unlike file extensions which can be easily changed, magic numbers are embedded in the binary data and cannot be faked.
The tool reads your file's first 32 bytes and compares them against a database of 50+ known file signatures to identify the format with high confidence. ZIP files are additionally inspected to detect DOCX, XLSX, PPTX, APK and JAR sub-types.
All analysis runs entirely in your browser using the Web Crypto API. Your files are never uploaded to any server and never leave your device.
A magic number is a fixed sequence of bytes at the start of a file that identifies its format. PNG files always start with 89 50 4E 47 regardless of their extension.
No. This tool reads the actual binary content, not the filename. A .exe renamed to .jpg is still correctly identified as an executable.
This tool detects file type mismatches commonly used to disguise malware. It does not perform antivirus scanning.
SHA-256 generates a unique fingerprint of your file. Compare it against the official hash published by the developer to verify the file has not been tampered with.