Protect PDF
Protect PDF files with a password using this free online PDF encryption tool: AES-256 encryption, plus optional print, copy and edit limits. No upload.
Processed locally in your browserHow?
This tool runs in this browser tab. The files, text and values you enter are not uploaded to clkr.work servers — closing the tab clears them. Anonymous usage events (such as which button was pressed) are counted, never your content. Privacy policy
What next?
Found it useful? Share Protect PDF
Free, no sign-up, works in the browser — send it to a friend or add it to your site.
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How to use Protect PDF
- 1Drop your PDF onto the page or tap Upload PDF
- 2Type a password twice and choose whether people can print, copy or edit
- 3Press Protect PDF and download the password-protected file
Frequently asked questions
How do I password protect a PDF for free?▾
Upload the PDF, type a password twice and press Protect PDF. The downloaded file asks for that password every time it is opened.
How secure is the encryption?▾
The PDF is encrypted with AES-256, the strongest standard PDF encryption. Use a long password with numbers and symbols for the best protection.
Can I stop people from printing or copying?▾
Yes. Untick Print the document or Copy text and images. Most PDF readers respect these limits after the password is entered.
Will it open in Adobe Reader and on phones?▾
Yes. AES-256 PDFs open in Adobe Acrobat Reader, Chrome, Edge, Safari, macOS Preview and phone PDF apps.
What if I forget the password?▾
The password cannot be recovered, so keep a copy of the original PDF or store the password somewhere safe.
Embed Protect PDF on your website▾
Paste this snippet into your page. The embedded tool runs in your visitor's browser and shows a small “Powered by clkr.work” link.