Password-protect your PDF with AES-256 encryption — set an open password and control printing, copying and editing permissions. Runs entirely in your browser.
Drop your PDF here or click to browse
Files are processed entirely in your browser — nothing is uploaded to any server
Click the upload area or drag and drop your file. Upload your PDF, set an open password (required to view the file), then optionally restrict printing, copying and editing before downloading.
Adjust the tool options to match your requirements — all settings are explained with helpful labels and previews where applicable.
Click the action button to process your file instantly in your browser. Download the output — no waiting, no email, no account required.
The tool uses AES-256 encryption, which is the same standard used by governments, banks and defence organisations worldwide. AES-256 is considered computationally unbreakable with current technology — a brute-force attack on AES-256 would take longer than the age of the universe even with supercomputers. For most commercial and personal use cases, AES-256-protected PDFs provide exceptionally strong security.
An open password (also called a document password or user password) is required to open and view the PDF at all — without it, the file cannot be read. A permissions password (also called an owner password) allows the file to be opened but restricts specific actions: printing, copying text, editing content or adding annotations. You can set one or both. Setting only a permissions password with no open password means anyone can view the file but cannot perform restricted actions.
Yes — this is one of the most common PDF protection settings for distributing confidential reports or licensed content. Set a permissions password and disable printing while leaving viewing enabled. The recipient can open and read the document but cannot produce physical or digital copies. Note that screen capture is not preventable through PDF permissions — for absolute copy prevention, watermarking is the more reliable approach.
If you forget the open password, the PDF is inaccessible — there is no recovery mechanism without the password. AES-256 encryption means brute-force attacks are not practically feasible for strong passwords. Always store your passwords securely in a password manager such as Bitwarden, 1Password or Dashlane. We strongly recommend you keep a note of any password you set before downloading the protected file.
For AES-256 encryption to be effective, use a strong password: at least 12 characters, combining uppercase letters, lowercase letters, numbers and symbols. Avoid dictionary words, names, dates and keyboard patterns. The encryption strength of AES-256 is theoretically maximum — the practical weakness is always the password itself. A short or simple password can be brute-forced much more quickly than a strong random one.
Yes — AES-256 encrypted PDF files are supported by all major PDF readers: Adobe Acrobat Reader (all versions from 9+), Preview on macOS, Foxit PDF Reader, PDF-XChange Viewer, Chrome PDF viewer, Firefox PDF viewer, Edge built-in PDF reader, iOS Files app, and most Android PDF readers. Some very old PDF readers may only support 40-bit or 128-bit RC4 encryption — AES-256 requires PDF 1.7 format which has been standard since 2006.
No — to add or change the protection on an already-protected PDF, you must first remove the existing protection using our Unlock PDF tool (which requires the current password). Once unlocked, you can apply new protection settings with a new password. This two-step process ensures that you have legitimate ownership of the document before modifying its security settings.
No — PDF password protection and permissions settings cannot prevent screenshots or screen capture. A user with screen access can always capture what is displayed. For truly sensitive content, the best protection is combining password access control (open password), copy restriction (permissions password), and a visible or invisible watermark so that any leaked copy can be traced back to the recipient.
There is no file size limit imposed by this tool — processing happens in your browser and is limited only by your device\ available RAM. In practice, PDF files up to 500MB have been processed successfully on modern computers with 8GB+ RAM. Very large files (500MB+) may be slow to process or may exhaust browser memory on older or lower-spec devices. For very large files, splitting before protecting may help.
Absolutely not — the entire encryption process runs locally in your browser using the PDF-lib JavaScript library. Your document never leaves your device. This is critical for sensitive documents such as legal contracts, financial reports, HR records and medical records. No login is required and nothing is stored, logged or retained on any server.
