Drop a file here or click to upload
Any file type — images, executables, archives, documents, etc. (First 256 bytes inspected)
| Hex Signature | Format | Extensions | Status |
|---|
Every file on your computer has a hidden fingerprint in its first few bytes — a "magic number" that reveals its true identity, regardless of its filename extension. This concept powers the file command in Linux, forensic analysis tools, and security scanners. But most people never see how it works. File Fingerprint makes binary forensics accessible and visual — you can literally see the bytes that identify a PNG, an executable, or a PDF.
An interactive file forensics tool that reads any file (or hex string) and inspects its binary header byte-by-byte. It detects the real file type from magic bytes, compares the detected type against the filename extension to expose spoofing, and lets you explore how file format signatures work. Built as an educational explorer for digital forensics and binary format understanding.
When you upload a file, the tool reads the first 256 bytes as a binary ArrayBuffer. It then checks these bytes against an internal database of 80+ known file signatures — each with its hex pattern, offset, and metadata. The matching algorithm checks multi-byte patterns at various offsets (not just the first byte). For example, PNG files start with 89 50 4E 47 0D 0A 1A 0A, ZIP archives (including .docx and .xlsx) start with 50 4B 03 04, and PDFs begin with 25 50 44 46 2D.
89 50 4E 47 0D 0A 1A 0A and click Analyze.