Network status / sealed Nothing leaves your browser. Each file is read by this page and never sent anywhere. Open your browser's network tab and watch: nothing leaves while you use it.

Inspection notes / 03

What the scanner is looking for.

Sniff does not guess whether a file is “safe.” It shows you what is actually present so you can make that call yourself.

What Sniff reads

The parts of a file nobody opens

Word, Excel and PowerPoint files are archives. Inside them sit author names, the company that licensed the software, total editing time, comments, tracked deletions, hidden rows and a rendered preview of the first page. PDFs keep a document information block, an XMP record of every tool that touched them, and often earlier versions of themselves. Photos keep the camera, the lens, the serial number and, very often, the exact coordinates.

What it will not do

It does not upload your file. Everything happens in the page.
It does not fetch map tiles. Location is drawn from a country outline stored on this site, so no server learns where your photo was taken.
It does not write HEIC or TIFF. Those two are read only, because stripping them would mean re-encoding the picture.
It does not write PDFs yet. Reading one is safe. Rewriting one badly leaves the old data recoverable, so that work is going into Ookii Drop instead.
It cannot tell you a file is safe. It can only tell you what it found.

When to use it

Before a document goes to a client, a counterparty or a public site.
Before a photo goes anywhere at all, if it was taken on a phone.
After a review round, to check no tracked deletions or comments survived.
When a file came from someone else and you want to know what it brought with it.