Drop a PDF file here or click to browse
Select a PDF to password-protect
Drop file to add
Strength
Passwords do not match.
Encryption: RC4 128-bit (PDF Security Handler Rev 3)
Permissions (unchecked = restricted)
What does RC4-128 protect?
| Protection | Protected | Not protected |
|---|---|---|
| Open password required | Yes | |
| Permission restrictions | Yes | |
| Content encryption | Yes | |
| Brute-force resistance | Moderate | |
| Government-level security | Use AES-256 |
RC4-128 is suitable for general use: password-protected sharing, preventing casual copying. For highly sensitive documents (legal, medical, classified), use dedicated software with AES-256 encryption.
Encrypting...
0%
Original:
Protected:
RC4 128-bit |
Verify password works
Files processed locally — never uploaded
How it works
Run this tool in three short steps.
01
Upload PDF
Drop your PDF or click browse.
02
Set password & permissions
Enter a password and choose which actions to allow.
03
Download protected PDF
Click Protect and download your encrypted PDF.
Questions
What people ask before they use this tool.
How does PDF password protection work?
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.
Can I set different permissions for printing and copying?
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.
Are my files uploaded anywhere?
No. PDF encryption happens in your browser using JavaScript, and your PDF and password are not uploaded to our servers during processing.
What encryption standard is used?
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.
Can I remove the password later?
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.
What is the difference between the user password and the owner password?
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.
How is this different from Adobe Acrobat encryption?
Adobe Acrobat supports a broader document-security workflow, including AES-256 options. This tool uses RC4-128 in a browser workflow for lighter protection needs. For stricter security requirements, dedicated software with stronger encryption options may be more appropriate.
Can I protect multiple PDFs at once?
Currently this tool processes one file at a time. Upload, set the password and permissions, download, then repeat for the next file.
What happens if I forget the password?
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.
Will the file size change after protection?
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 <a href="/compress-pdf">PDF Compressor</a> before protecting.
Can I protect a PDF I merged or split?
Yes. Use our <a href="/merge-pdf">PDF Merger</a> or <a href="/split-pdf">PDF Splitter</a> first, then upload the result here to add password protection.
Is the "Generate" button password truly random?
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.
Can I restrict only printing but allow copying?
Yes. Each permission (printing, copying, editing, form filling) is an independent checkbox. Check or uncheck any combination to match your needs.
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Coda One's PDF Protector lets you add password protection and encryption to any PDF file. Choose which permissions to allow, including printing, copying, editing, or form filling. Generate a strong random password or use your own, then download the encrypted PDF. Processing happens in your browser using RC4 128-bit encryption.