How to protect PDF with a password online
To password protect a PDF, open one or more files and type the password readers will enter; a strength meter shows how safe it is. The Advanced tab adds a separate permissions password that can block printing, editing, copying, comments, or form filling, with or without an open password. Click Protect PDF. Every file is encrypted with AES-256, and neither the files nor the passwords ever leave your device.
Step by step
Three steps. Most files take a few seconds.
Step 1: Open your PDF
Drop one or more files onto the page.
Step 2: Set the password
Type it twice and watch the strength meter. In Advanced, add a permissions password and tick what to block.
Step 3: Protect and download
Click Protect PDF. The encrypted file downloads to your device.
Why use this tool
Strong encryption
AES-256, the current PDF standard, supported by Adobe Reader, Preview, Chrome, and phones.
Permissions
Allow or block printing, copying text, editing, and form filling.
Password stays with you
We never see or store the password, so it cannot be logged or leaked.
Your file is never stored
Your document is used only to produce the result you asked for. Once the download is ready and you leave the page, the file is gone. There is no copy to keep, no account that holds it, and nothing to delete later.
That makes it safe for invoices, contracts, bank statements, ID scans, medical records, and anything else you would rather keep to yourself.
Read how it worksFrequently asked questions
How do I put a password on a PDF for free?
Open Protect PDF, add the file, enter a password, and click Protect PDF. The protected file downloads immediately.
What is the difference between a user password and an owner password?
The user password is required to open the file. The owner password unlocks the permissions, for example to allow printing again. If you only set one, it is used for both.
Can the password be recovered if I forget it?
No. AES-256 encryption cannot be reversed without the password, and we never see it. Store it somewhere safe.
Can I remove the password later?
Yes. Use the Unlock PDF tool with the password to save an unencrypted copy.
Is it safe to use this with confidential documents?
Yes. Your file is used only to produce the result you asked for and is never stored. We do not keep copies, read the contents, or share them with anyone. Once you download the result and close the page, the file is gone.
Is this really free?
Yes. Every tool on PDF Editor Box is free to use without signing up. We may show an ad outside the work area, but we never gate features, add watermarks to your output, or limit how many files you process.