Protect PDF
Add a password to your PDF and keep it private. The result has no watermark.
Drop your PDF here
or click to browse — up to 10 MB free
Everything you need to secure a PDF
Password-protect any PDF with 256-bit AES encryption.
Strong AES-256 encryption
Your PDF is locked with industry-standard 256-bit AES encryption — a standard also used in banking.
Password to open
Only people with the password can open and read the document. Keep sensitive files truly private.
Works everywhere
The protected PDF opens in any reader on Windows, Mac, Linux, Android and iOS — nothing to install.
Private & secure
Files are sent over an encrypted connection, scanned for malware and auto-deleted within 1 hour.
Keeps quality
Encryption never touches your content — text, images and layout stay exactly as they were.
Free to use
There is no watermark. The free plan covers files up to 10 MB; upgrade for larger files or more volume.
How to password-protect a PDF in 3 steps
Choose a password, protect, download.
Upload your PDF
Drag & drop or pick the PDF you want to protect.
Set a password
Choose a strong password and confirm it.
Download
Click protect, then download your encrypted PDF.
When you need to protect a PDF
From confidential contracts to personal records — keep prying eyes out.
At work
- Secure contracts, invoices and payslips before emailing them.
- Protect financial reports and board documents shared with partners.
- Lock HR files, offer letters and confidential agreements.
- Keep tenders, NDAs and legal documents for authorized eyes only.
At home
- Password-protect bank statements and tax documents.
- Secure copies of your passport, ID and certificates.
- Keep medical records and personal letters private.
- Protect any PDF before uploading it to the cloud.
What actually happens when you protect a PDF
What the encryption covers and what it doesn't.
What "protecting" actually adds
This tool applies 256-bit AES encryption, a standard also used in banking and government, to require a password before the PDF can be opened. This is meaningfully stronger than the weaker 40-bit or 128-bit encryption some older PDF tools still default to.
Setting permissions vs. setting a password
You can require a password just to open the file, restrict actions like printing, copying text, or editing even after opening, or both at once. These are independent settings — you could, for example, let anyone open the file but block printing.
Can the protection be removed later?
Yes, with our Unlock PDF tool — but only if you know the password you set. There's no backdoor or master key; if the password is lost, the file's content is genuinely inaccessible, which is the entire point of real encryption.
Does protecting change the file content?
No — protection only adds an encryption and permissions layer around the existing content. Text, images, and formatting are completely unchanged; the file just requires a password and enforces the permission rules you set.
Protecting an already-protected PDF
If a PDF already has a password, you'll need to unlock it first before applying new protection settings — you can't stack a second password on top of an existing one. Unlock, then re-protect with your new settings.
Choosing a strong password
The encryption is only as strong as the password protecting it — a short or common password is the weak point, not the encryption algorithm. Aim for at least 12 characters mixing letters, numbers, and symbols, and avoid reusing a password you use elsewhere.
Frequently asked questions
Password-protect PDF online — free and secure
Our Protect PDF tool lets you add a password to any PDF document so only people who know the password can open it. The file is encrypted with strong 256-bit AES encryption, a standard also used in banking and government. The file stays protected wherever it travels.
Upload your PDF, choose a password, and download the protected file. The encryption is applied to the file itself, so the password is required every time the document is opened — on any device, in any PDF reader, by email or in the cloud.
Safe, private and lossless
Uploaded files are transferred over a secure encrypted connection, scanned for malware, and automatically deleted from our servers within 1 hour. We never store your password. Encrypting a PDF is completely lossless, so your text and images keep their original quality. There is no watermark.
Protect your PDF
Upload your file and lock it with a password. Free, with no watermark.