Protect a PDF in three steps
- Choose your PDF and check its filename and page count.
- Enter a unique password twice, or generate and save a random password.
- Protect the PDF, then download the verified encrypted copy.
What does password protection do?
The saved file uses AES-256, PDF security revision 6. It requires your password to open. Printing, copying and editing remain allowed after opening; these reader permissions are not a reliable way to prevent sharing. Use a long, unique password and send it separately from the file.
A separate random internal owner password is generated locally, with all document permissions allowed. You only need the opening password you chose. ToolzMate does not keep passwords or provide password recovery. Save your password before processing; the fields clear after success or cancellation. Undo changes can restore the previous source and completed download after editing, replacement or Clear; passwords are never restored. A successful new export ends this recovery.
Original content and compatibility
The original file stays unchanged. The encrypted copy retains pages and document properties, but its bytes and size change. The tool verifies that an empty password fails and your selected password opens the saved file with the expected page count. Older PDF readers may not support AES-256 revision 6.
Privacy and limits
Use a plain, unsigned PDF up to 20 MiB and 100 pages. Decoded metadata is limited to 1 MiB and declared PDF/A files are rejected. Encrypted output is limited to 40 MiB; processing has a 60-second deadline and can be cancelled. Signed, already encrypted and interactive-form PDFs are rejected. PDF/A documents cannot be encrypted while retaining PDF/A compliance.
Passwords support at least 8 characters and at most 127 UTF-8 bytes; non-English characters may use multiple bytes. No spaces are trimmed or characters silently truncated. Files and passwords are processed locally, without uploads, analytics events containing content, or browser-storage persistence.