Security
Password protect a PDF
Add a password a PDF asks for before it opens, with 256 bit AES encryption, and block printing, copying, or editing. Free, no upload, runs in your browser.
How to password protect a PDF
Three steps, and neither your file nor your password leaves your device.
- 1
Drop a PDF into the drop box
Or click to browse for it. Nothing is uploaded.
- 2
Type the password it should ask for
Tick No printing, No copying, or No editing if readers should not.
- 3
Click Protect PDF and download it
Encrypted with 256 bit AES. Your original stays as it was, without a password.
When to password protect a PDF
A PDF goes wherever it is sent and stays there for years. These are the times it should ask who is opening it.
Tax returns, payslips, and medical records by email
An attachment sits in inboxes and sent folders long after it is read. With a password, a forwarded or leaked copy is unreadable. Send the password another way, by text or on the phone.
A shared link that could travel
Anyone with a cloud link can pass it on. The file itself still asks for the password, wherever the link ends up.
A file on a shared computer or a USB stick
A family laptop, an office PC, or a stick that gets lost. The pages cannot be read without the password, whoever finds the file.
A handout that should not be printed or copied
Tick No printing or No copying with no password, and the file opens for anyone. Most readers honor the request, though some programs ignore it.
Letters for one person each
HR letters, invoices, or results, each with its own password, so only the person it is for can open it. The password is never saved, here or anywhere.
No catch
Protect as many PDFs as you like
Add a password to one file or to every file you send. There is no daily limit and nothing to sign up for, and your password stays on your computer.
- Daily limitNoneUse it as much as you like.
- Sign upNeverNothing to fill in.
- WatermarkNeverYour file comes back clean.
- WaitingStarts the moment you dropNothing to send first.
- Your passwordStays on your computerIt is not sent or saved.
- Daily limitOften 1 or 2 free a dayThen a paid plan.
- Sign upOftenTo keep going or to download.
- WatermarkSome add oneUnless you pay to remove it.
- WaitingSend it, then waitSlow for large files.
- Your passwordTyped into their websiteWith the file it locks.
Related tools
Each one works the same way: free, in your browser, with nothing uploaded.
Protecting a PDF, answered
Your files stay privateIs my file or my password uploaded anywhere?+
No. Your browser encrypts the PDF on your own computer or phone. Neither the file nor the password is sent anywhere, and the password is not saved.
Is it free to password protect a PDF here?+
Yes. There is no watermark, no file limit, and no account. The work happens in your browser, so there is nothing for us to charge for.
How strong is the protection?+
The file is encrypted with 256 bit AES, the strongest encryption a PDF can have, which every current PDF reader opens. Without the password the pages cannot be read. A long password matters more than anything else: a short, common one can be guessed.
What if I forget the password?+
Then the protected copy cannot be opened, by you or by us. Nobody holds a copy of the password. Your original file is untouched, so keep it until you are sure of the password.
Will the pages change?+
No. Text, images, links, bookmarks, and form fields stay exactly as they were. Only the encryption is added.
Can I stop people from printing or copying it?+
Yes. Tick No printing, No copying, or No editing, with a password or without one. Adobe Acrobat, Preview, and browsers respect these, but they are a request written in the file, not a lock: some programs ignore them. Only the password actually keeps people out.
How do I remove the password later?+
Open the file in Unlock PDF and type the password once. It saves a copy that opens without one.
Does it work on iPhone, Android, Mac, and Windows?+
Yes. It runs in any current browser, Chrome, Safari, Edge, or Firefox, on a computer, a phone, or a tablet. There is nothing to install and no account to make.
Is there a file size limit?+
No. There is no set limit and no daily cap. Your own device does the work, and files of a few hundred megabytes are fine on a laptop.