Question 1

How does PDF password protection work?

Accepted Answer

The tool encrypts your PDF using RC4 128-bit encryption with the password you set. Anyone trying to open the file will need to enter the correct password first.

Question 2

Can I set different permissions for printing and copying?

Accepted Answer

Yes. You can choose which actions to allow — printing, copying text, editing, or form filling — using the permission checkboxes. Unchecked permissions will be restricted even for users who know the password.

Question 3

Are my files uploaded anywhere?

Accepted Answer

No. All encryption happens entirely in your browser using JavaScript. Your PDF and password never leave your device.

Question 4

What encryption standard is used?

Accepted Answer

The tool uses RC4 128-bit encryption (PDF Security Handler Revision 3), supported by all PDF readers. Note: RC4 provides standard-level protection suitable for casual use. For highly sensitive or confidential documents, use dedicated security software with AES-256 encryption.

Question 5

Can I remove the password later?

Accepted Answer

Yes. Open the protected PDF with the password in any PDF reader, then use "Save As" or "Print to PDF" to create an unprotected copy.

Question 6

What is the difference between the user password and the owner password?

Accepted Answer

The user password (also called the "open" password) is required to open the file at all. The owner password controls permissions like printing and copying. This tool sets an owner password to restrict permissions while keeping the file openable without a password — or you can set both for full access control.

Question 7

How is this different from Adobe Acrobat encryption?

Accepted Answer

Adobe Acrobat supports AES-256 encryption and requires a subscription. Coda One uses RC4-128, which is sufficient for casual protection and runs entirely in your browser for free. For government-level or legal confidentiality, use dedicated software with AES-256.

Question 8

Can I protect multiple PDFs at once?

Accepted Answer

Currently this tool processes one file at a time. Upload, set the password and permissions, download, then repeat for the next file.

Question 9

What happens if I forget the password?

Accepted Answer

There is no recovery mechanism. The password is applied locally and never stored anywhere. Make sure to save the password in a password manager or use the "Copy password" button after encryption.

Question 10

Will the file size change after protection?

Accepted Answer

Slightly. Encryption adds a small overhead (typically 1-5% larger). The content itself is not recompressed. If you need to reduce size first, use our PDF Compressor before protecting.

Question 11

Can I protect a PDF I merged or split?

Accepted Answer

Yes. Use our PDF Merger or PDF Splitter first, then upload the result here to add password protection.

Question 12

Is the "Generate" button password truly random?

Accepted Answer

Yes. It uses the Web Crypto API (crypto.getRandomValues) to generate a 20-character password with uppercase, lowercase, digits, and symbols. This is cryptographically secure randomness.

Question 13

Can I restrict only printing but allow copying?

Accepted Answer

Yes. Each permission (printing, copying, editing, form filling) is an independent checkbox. Check or uncheck any combination to match your needs.

Protection	Protected	Not protected
Open password required	Yes
Permission restrictions	Yes
Content encryption	Yes
Brute-force resistance		Moderate
Government-level security		Use AES-256

Protect PDF

Drop a PDF file here or click to browse

Drop file to add

How It Works

Upload PDF

Set password & permissions

Download protected PDF

FAQ

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