Identify a file's true type by its magic bytes.
Tip: use samples, upload, copy, download, and send-to actions inside the workspace where available.
File Signature Checker is a free, browser-based tool that helps you understand a dataset at a glance. Identify a file's true type by its magic bytes. It's built for speed and privacy: Everything runs locally in your browser — your data is never uploaded to a server. No sign-up, no installs, and no daily limits.
Profile the data first so missing values, types, duplicates, and outliers are visible before you edit it.
Review the preview, copy or download the result, and keep everything local in your browser.
MIME Type Detector: Sniff a file's real MIME type and compare it to the declared type.
Open toolFile Checksum Generator: Verify file integrity with SHA-1/256/512 in your browser.
Open toolDense binary — machine code, images, or partially compressed data.
47 49 46 38 39 61 10 00 10 00 80 00 00 FF FF FF
GIF89a..........GIF (89a) files should end with 3B. It is absent, which points to a truncated download, an interrupted write, or deliberate tampering.
".gif" is a legitimate extension for GIF (89a).
Plain ZIP archive (.zip) — No format-specific marker entry was found, so this looks like an ordinary archive.
| Offset | Name | Method | Size |
|---|---|---|---|
| 0x0000002B | payload.exe | stored | 64 |