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Encrypt PDF Files

Browser-first

Encrypt PDF documents with RC4 128-bit encryption — set permissions, restrict access, protect sensitive content

Protect PDF Now
Start in browser Processed in your browser RC4 128-bit encryption

How It Works

1

Upload Your PDF

Drop or select a PDF file and start the first protection step directly from the page.

2

Set Password & Permissions

Enter a password and choose what actions to allow: printing, copying, editing.

3

Download Protected PDF

Your encrypted PDF is ready. Share it knowing only authorized people can open it.

Encrypt any PDF file with widely supported RC4 128-bit encryption directly in your browser. Set an encryption password and fine-tune permissions so printing, copying, and editing match your use case. The encryption process runs in JavaScript in your browser, and file content is not uploaded to our servers during that step. Compatible with major PDF readers including Adobe Acrobat, Chrome, Firefox, and Preview.

Frequently Asked Questions

What encryption standard does this tool use?
RC4 128-bit encryption with PDF Security Handler Revision 3. It is widely supported across major PDF readers and provides solid protection for business and personal documents.
Is my PDF uploaded to a server for encryption?
No file content is uploaded to our servers during encryption. All encryption runs locally in your browser using JavaScript.
What is the difference between user password and owner password?
A user password (open password) is required to open the PDF at all. An owner password controls permissions — what actions are allowed even after the PDF is opened. This tool sets both to the same value for simplicity, giving you full open-password protection plus permission control.
Can I encrypt a PDF that is already encrypted?
The tool can load previously encrypted PDFs if you provide the original password. For a smoother first pass, start with an unencrypted PDF when possible. If you need to change the password on an already-protected file, first save an unprotected copy from your PDF reader, then encrypt it here.
What file size limit does the tool support?
There is no hard limit — the tool processes files in your browser memory. Most devices handle PDFs up to 50-100 MB without issues. For very large files (200 MB+), performance depends on your device and browser.
Try Password Protect PDF

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