Password Protect PDF
Add a real open password and permission restrictions to a PDF, entirely inside your browser.
How does this PDF protector work?
Every page is re-rendered as an image, then rebuilt into a new PDF that's encrypted with the password and permissions you choose, using real AES encryption — the same standard PDF readers use to enforce a genuine open password, not a cosmetic lock. Rendering pages to images first is what makes real client-side encryption possible without a server: the underlying encryption library used here only knows how to build brand-new PDFs, not add encryption to an arbitrary existing one. The trade-off is the same as the Compress PDF tool — text in the protected file is no longer selectable or searchable.
GuideHow to use it
Features & benefits
Why this runs entirely in your browser
PDF files often contain sensitive or confidential documents, so nothing is uploaded to a server. Rendering, encrypting, and rebuilding the PDF all happen locally using your browser's own processing power, directly in the tab — including your password, which is never sent anywhere.
Common uses
Locking a document before emailing it, restricting who can open a sensitive report, or preventing casual printing or copying of a file you're sharing.
Frequently asked questions
A few things people usually want to know before trusting the numbers.
No. Every page is redrawn as an image before encryption, so the protected PDF is effectively a set of encrypted pictures rather than real text — you won't be able to select, search, or copy text from it afterward, even with the correct password.
It's a real password enforced by AES encryption, the same mechanism standard PDF readers rely on — anyone without the password won't be able to open or view the file's contents at all, not just be blocked by a permissions notice.
There is no way to recover it. Since the password never leaves your browser and isn't stored anywhere, losing it means the protected PDF can't be opened again — keep a copy of the original file and the password somewhere safe.
PDFs that already require a password to open can't be processed, since the tool can't read their contents without that password first. Remove the existing protection before adding a new one.
No. All rendering and encryption happens locally in your browser using JavaScript running on your own device. Nothing you upload or type here is ever sent to a server, stored remotely, or shared with anyone.