Protect PDF
Add a password to a PDF to restrict opening or editing. Free, browser-based encryption — see the tool for encryption details.
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YOYOPDF provides browser-based tools for common PDF and image tasks. Fast, easy and free.
Powerful Tools to Work with PDFs
YOYOPDF provides browser-based tools for common PDF and image tasks. Fast, easy and free.
Local by Design
Document contents stay on your device while tools process them in the browser; YOYOPDF does not upload your files.
Blazing Fast
Our tools are optimized for speed to save your time and increase productivity.
Works Across Devices
Use YOYOPDF in a modern desktop, tablet or mobile browser. No installation required.
Always Free
All tools are completely free to use. No hidden charges, no sign up needed.
Everything You Need. All in One Place.
Use YOYOPDF for common PDF and image tasks while keeping document processing on your own device.
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View all tools →Why use Protect PDF?
A password on a PDF is a simple gate against casual access — the file only opens for someone who has the password you gave them, not for anyone who happens to receive the attachment.
A file is going somewhere less controlled than a private inbox
Cloud storage links, shared drives, and forwarded emails all widen who might end up with a copy — a password limits who can actually open it.
Printing or editing needs to stay restricted
Permission flags can lock down printing or editing even for readers who have the open password, in readers that respect those flags.
Basic access control is the actual requirement
For everyday documents that just need a gate — not vault-grade confidentiality — a standard PDF password is a fast, no-install way to add one.
How it works
Upload
Add the PDF you want to protect. Nothing is sent anywhere at this step.
Set a password
Choose an open password, and optionally set permission restrictions like printing or editing.
Encrypt
The file is encrypted locally in your browser using the PDF format's Standard Security Handler.
Download
Save the password-protected PDF. Share the password separately from the file itself.
Key features
Open password
Require a password before the document will open at all in a compliant PDF reader.
Permission flags
Restrict printing or editing independently of the open password, for readers that honor those flags.
Runs in your browser
Encryption happens locally — your file and password are never uploaded to a server.
No sign-up
Open the tool and set a password immediately — no account, no email, no waiting.
Free
Protect as many files as you need, with no watermark added to the result.
Who uses Protect PDF?
HR
Add a password to an offer letter or personnel file before emailing it.
Finance
Gate a statement or invoice sent over email so only the intended recipient can open it.
Small business
Restrict editing on a quote or contract while still letting the client view and print it.
Freelancers
Password-protect a draft deliverable before sharing it for client review.
Frequently asked questions
How strong is the encryption?
Protect PDF uses the PDF format's original Standard Security Handler (40-bit RC4). It's suitable as basic access control, not as strong confidentiality for highly sensitive documents.
Is my file uploaded to encrypt it?
No, encryption happens locally in your browser — the file and password are never sent anywhere.
Can I restrict printing or editing without a password to open?
Yes, permission flags can be set independently of the open password, though they're honored only by readers that respect them.