Protect PDF
Password-protect and encrypt any PDF right in your browser โ no upload, no signup.
Drag & drop your PDF here, or click to choose. Your file and password never leave your browser โ nothing is uploaded.
Set a password
The owner password grants full access and lets you change these permissions later. Leave blank to reuse the password above.
Allow these actions once the PDF is opened
Protect PDF adds a strong password to your PDF and encrypts its contents so only people who know the password can open it. Unlike iLovePDF or Smallpdf, which upload your file to their servers, this tool runs entirely in your browser โ your document and the password you choose never leave your device, which is the whole point of securing a file. Set a separate owner password and choose exactly what readers are allowed to do once it is open: printing, copying text, modifying, annotating and filling forms. There is no signup, no watermark and no file-size limit beyond your own browser memory.
Frequently Asked Questions
How do I password-protect a PDF?
Drag your PDF in, type a password and confirm it, then click Protect & download. The encrypted PDF is saved to your downloads. Anyone opening it afterward must enter that exact password.
Is my file or password uploaded anywhere?
No. The entire process runs in your browser using client-side encryption. Your PDF and the password are never sent to a server, logged or stored โ which makes this far more private than tools that upload the file you are trying to secure.
What is the difference between the user password and the owner password?
The user (open) password is required to open the file and is restricted by the permissions you set. The owner password grants full access and lets you change permissions later. If you leave the owner password blank, it defaults to your open password.
What encryption does this use?
It applies AES encryption to the PDF and writes a standard /Encrypt dictionary, so the file is genuinely protected and cannot be opened in any PDF reader without the password โ not just visually hidden.
Can I control printing or copying after the PDF is opened?
Yes. Under Advanced options you can allow or block printing, copying text, modifying, annotating and filling forms. These permissions are enforced for anyone opening the file with the user password.
Can I recover the password if I forget it?
No. Because nothing is uploaded, there is no copy of your password anywhere โ we cannot reset or recover it. Store it somewhere safe before sharing the protected file.
My PDF won't load โ why?
If the file is already password-protected or encrypted, it must be unlocked first before you can re-protect it. Corrupt files will also fail. Unlock or repair it, then try again.
Does it work on mobile and offline?
Yes. It runs in any modern mobile or desktop browser, and because all processing is local it keeps working even with a flaky connection once the page has loaded.