Protect PDF with a password for free
Add a password to a PDF before emailing or sharing it: only people who know the password can open it. AES-256 encryption, the same as current Acrobat.
Your PDF never leaves your device: everything happens in your browser, with no upload, no sign-up, no watermark and no metadata.
Drop your PDF here
or click to choose · the file never leaves your device
More PDF tools
See all PDF tools →How to password protect a PDF
Drop the PDF, type the password twice and tap Protect PDF. The new file asks for the password in any reader: Acrobat, Chrome’s and Edge’s viewers, your phone. Without the password the content is unreadable — it isn’t just a lock screen.
Encryption is AES-256 (the PDF 2.0 standard), done in your own browser: the password and the document never pass through any server. So keep the password safe — nobody can recover it, not even us.
Under Restrictions you can block printing, copying text or editing, even for people who have the password. Common PDF readers respect these restrictions.
Sent it with a password and now need it open? Unlock PDF removes the password (as long as you know it). For documents with client data, add a Watermark before protecting.
Example: the medical report sent by chat
A medical report is going to a patient over a messaging app. Set a password you agreed on by phone, such as their date of birth, and tap Protect PDF. If the file ends up on the wrong phone, the content is unreadable without the password. In Restrictions, you can also block printing or copying text.
Questions about password-protecting PDFs
Which password should I choose?
One you agree with the recipient through another channel (phone, in person). Don’t send the password in the same message as the file.
I forgot the password. Can it be recovered?
No. The AES-256 encryption happens in your browser and nobody stores the password, including us. Keep a copy of the PDF without a password.
Does a password-protected PDF open in any reader?
Yes: Acrobat, the Chrome and Edge readers and phone apps all ask for the password and show the document.
What’s the difference between a password and restrictions?
The password stops it opening. Restrictions let it open but block printing, copying or editing in readers that honor the rule, which the common ones do.
Pages read with PDF.js (Mozilla, Apache-2.0 license) and the PDF written with pdf-lib (Andrew Dillon, MIT license), inside your browser. Encryption uses your browser’s own AES-256 (Web Crypto).