Observed arrival · 2026-11-13
What Is This File? Reads the bytes, not the filename
A browser-based tool that identifies unknown file types from their signatures, including files with misleading or missing extensions.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- People trying to identify unfamiliar or mislabeled files
- Worth noticing
- For ZIP-based formats, it checks one level inside the container; the page says it compares against more than a hundred signatures.
Field notes
The page explains that filenames are labels, while a file’s opening bytes can reveal its format. It says the scanner recognizes text formats from their first lines and checks inside ZIP containers for formats such as Word documents, Android apps, EPUB books, and Apple Pages files. Its safety guidance distinguishes a misleading extension from malware detection: a correctly identified file can still be harmful.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue