Upload Guard by Barnabs Sudy (Rivia)

Upload Guard helps prevent accidental uploads of the wrong or unprotected files. You choose which websites it watches, and what every uploaded file must satisfy — for example, that it's password-protected, or that its filename matches a pattern.

It checks files both when picked from the file dialog and when dragged-and-dropped. A file that fails a check is blocked before it leaves your browser, with a clear explanation of why.

EVERYTHING RUNS LOCALLY
Files are inspected inside your browser by reading their bytes. Nothing is uploaded to, sent to, or stored on any server. Upload Guard makes no network requests and collects no data.

WHAT YOU CAN REQUIRE (PER SITE)
• Password-protected / encrypted files — detects encrypted PDF, Microsoft Office (Word/Excel/PowerPoint), and ZIP files.
• Filename pattern — require names to match a glob, e.g. invoice_*.pdf.
• Block unsupported file types — reject anything that can't be inspected.
• Allow override — turn a hard block into a warning the user can choose to bypass.

Each check is optional and independent. A site with no checks enabled does nothing — uploads pass straight through.

EASY TO MANAGE
• Click the toolbar icon to open settings.
• Add as many sites as you like, each with its own rules.
• Export your configuration to a file and import it on another machine — handy for sharing a standard ruleset across a team.

PRIVACY
Upload Guard does not collect, transmit, or sell any data. All processing happens on your device.