Protect PDF with a password.
Add 128-bit encryption to any PDF. Set an open password, restrict printing and copying. Runs entirely in your browser.
What does protecting a PDF do?
Password-protecting a PDF encrypts the file so it cannot be opened without the correct password. The encryption is applied at the file level — a protected PDF looks like scrambled data to anyone without the key, regardless of which application they try to open it with. Standard PDF readers (Adobe Acrobat, macOS Preview, browser PDF viewers) all enforce the password prompt before showing any content.
There are two distinct types of PDF passwords. A user password (also called an open password) is required to open and view the document at all. An owner password controls permissions — it restricts what an authenticated user can do with the document (printing, copying text, filling forms). Foliopress lets you set a user password, optionally restrict printing and copying, and generates a properly encrypted PDF using 128-bit RC4 encryption compatible with PDF 1.4 and above.
When should you protect a PDF?
Password protection is useful whenever you need to share a document with a specific person or group and want to prevent unauthorised access. Common scenarios include sending contracts or agreements that should only be read by the named parties, distributing confidential reports within an organisation, sharing financial documents, or archiving personal records you want to keep encrypted.
Restrictions (preventing printing or copying) are useful when you want recipients to read a document but not extract its content for use elsewhere — for example, distributing a proprietary report that should be read but not copied into other materials.
Encryption and privacy
All encryption happens locally in your browser using @cantoo/pdf-lib, a JavaScript PDF library that implements the PDF encryption specification. Your file and your password are never transmitted to any server. The encrypted output is generated in memory and downloaded directly to your device. No one else ever sees your file or your password.
Note that PDF encryption protects access — it does not prevent someone with the password from sharing the file further. For documents requiring strict distribution control, password protection should be combined with other access controls appropriate to your context.