How to protect a PDF with a password
- 1 Drop your PDF on the box, or click browse to choose it.
- 2 Type a password to open the PDF, then type it again to confirm.
- 3 Untick anything people should not do after opening it: print, copy, or edit.
- 4 Press Protect and download and keep the password somewhere safe.
Choosing a strong PDF password
Use a long passphrase of three or four unrelated words with a number, and send it separately from the file. Shrink large files first with Compress PDF, and if you need to change the password later, remove it with Unlock PDF and protect the file again.
- Never send the password in the same email as the file.
- Keep an unprotected copy somewhere safe.
- Restrictions are a polite barrier; the open password is the real lock.
Features
256-bit AES encryption
The strongest encryption in the PDF standard.
Optional restrictions
Block printing, copying or editing after opening.
Never uploaded
Encrypted on your device with qpdf running in the browser.
When to use it
Sending private documents
Protect bank statements, payslips, contracts and ID scans before emailing them. Send the password separately, for example by text message.
Sharing client files
Accountants, lawyers and HR teams can protect reports for each client. To shrink the file first, use Compress PDF.
Storing sensitive records
Keep tax returns and medical letters encrypted on shared computers or cloud drives.
Controlled handouts
Let people read a PDF but not print or copy it, knowing these restrictions rely on the reader software. To remove a password later, use Unlock PDF.
Related PDF tasks
Frequently asked questions
How secure is the password protection?
The PDF is encrypted with AES using a 256-bit key, the strongest method in the PDF standard. Security depends on your password, so use at least ten characters with a mix of words, numbers and symbols.
Can I recover a forgotten password?
No. Strong encryption means there is no back door, and we never see or store your password. Keep a copy of the original file or write the password down somewhere safe.
Do the print and copy restrictions really work?
They are respected by Adobe Acrobat, browsers and most PDF apps, but some software ignores them. Treat restrictions as a polite barrier; the password to open the file is the real protection.
What is the owner password?
PDF restrictions are protected by a second, owner password. This tool creates a long random one for you, so nobody can lift the restrictions just by knowing the password to open the file.
Will the protected PDF open on phones?
Yes. iPhone, Android, Windows and Mac PDF readers all support 256-bit AES encryption and will ask for the password.
Can I protect a PDF that already has a password?
Remove the existing password first with Unlock PDF, then protect it again with the new password.
Does protecting change the content or quality?
No. Text, images and layout stay exactly the same. Only encryption is added.
How should I send the password?
Send it by a different route than the file, such as a phone call or text message, so someone who intercepts the email cannot open the document.
Is my PDF uploaded to add the password?
No. The encryption runs inside your browser using a WebAssembly version of the open-source qpdf tool, so the file and password never leave your device.
How this tool works. These PDF tools run entirely in your browser using two widely used open-source libraries: PDF.js, the PDF engine built into Firefox, to read and render pages, and pdf-lib to create and edit files. Each tool is tested with typed documents, phone scans and photo-heavy files before it goes live, and nothing you open is sent to a server.
Built and reviewed by Hamza Farooq, founder and lead developer
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