Files move in both directions, and both are worth a rule.
An upload is a copy of your data on somebody else's server. A download is somebody else's code on your laptop. Capsulla keeps a list for each direction and refuses the transfer before it starts.
application/x-msdownloadapplication/x-apple-diskimage
.bat.ps1
The export that was only meant for a quick look
Database dumps into an online SQL formatter, customer exports into a free converter, source files into a code explainer. The upload is stopped before the first byte leaves, and the person sees why.
application/sqltext/x-python
.sql.csv.gz
The installer from the third result on the page
Downloads are cancelled mid-flight when the file is a type you do not allow. The list ships covering the things that run when double-clicked — executables, installers, disk images, shell and PowerShell scripts.
By what it is, or by what it is called
An entry is either a file type the browser reports or an extension such as .sql or .tar.gz. Neither covers everything on its own: a type catches a file somebody renamed, an extension catches the many files a browser reports no type for.
- Describe a category — “installers”, “database dumps” — and Generate with AI fills in the entries.
- A matching transfer is refused outright. There is no warn and no mask for a file.
Worth knowing
- Whitelisted hosts are exempt, so the tools your team is supposed to upload to stay out of the way.
- An event records the file name, type and size — never the file.
Other things people move
Stop the next leak before it leaves the browser.
Try it free for 14 days, no card needed. Start with one team and see what Capsulla catches in the first week.