Add password protection to your PDF files to prevent unauthorized access. Set a password and download the encrypted file. Everything happens in your browser — your password and files are never transmitted.
100% free and unlimited, with no sign-up, no watermarks, and no 5-file paywall. Files are processed locally in your browser and never leave your device.
Protect PDF is useful for school work, invoices, reports, contracts, scanned paperwork, client files, and any PDF task where you need a clean result without installing desktop software.
The file work happens in your browser. Your file is not uploaded to FilesFlow servers, which keeps private documents faster to process and easier to control.
For best results, start from a healthy source PDF and keep a backup of the original file. If the PDF came from a scanner, check the output carefully because scanned pages are usually image-heavy and can behave differently from text-based PDFs.
Choose a browser-based PDF tool when the job is simple, private, and urgent. For heavily edited legal documents, complex forms, or files that require professional prepress controls, a dedicated desktop editor may still be the better final step.
Protect PDF is built for fast browser-based PDF Tools work. Use a full PDF suite when you need signatures, redaction, OCR repair, complex forms, or print-production controls.