Protect PDF
Protect PDF add password to pdf without upload encrypt pdf locally aes 256 lock pdf with open passwordFiles stay on this device. Maximum 100 MB per file and 300 pages per operation.
Result
Require a password to open a PDF
Choose an unprotected PDF, enter the same password twice, and select Protect PDF. The local qpdf engine creates an AES-256 encrypted copy. Download it, close the browser preview, and test the password in a trusted PDF reader before sharing the file.
What password protection does
The output uses PDF standard encryption with a password required to open the document. Encryption protects file contents while the file is closed and the password remains secret. After an authorized reader opens it, the person can view the content and may be able to capture or reproduce what they can access.
Worked example: send a private statement
Choose the statement, create a unique password of several unrelated words, and protect the PDF. Send the file and password through separate channels, such as email for the file and a phone call for the password. Open the downloaded copy yourself before deleting or archiving any source.
Choose and store the password carefully
This page requires at least eight characters but length alone does not guarantee strength. Avoid names, dates, reused account passwords, and predictable substitutions. Awesome Tools does not receive or retain the password and cannot recover it. Store it in a password manager or another secure location before closing the page.
Encryption is not digital rights management
Password encryption cannot prevent every screenshot, print, copy, or redistribution after someone legitimately opens the document. It also does not prove who created the file or whether it changed. Digital signatures, access-controlled delivery systems, and organizational policies solve different trust problems.
Local processing and compatibility
The PDF and password stay inside this browser tab. A local WebAssembly build of qpdf performs encryption. Modern PDF readers should support the AES-256 output, but old or limited viewers may not. Existing digital signatures may become invalid after the file is rewritten.
Protect PDF FAQ
Can Awesome Tools recover my password?
No. The file and password are never sent to us.
Does this hide the filename?
No. Encryption protects PDF contents, not the filename or surrounding email metadata.
Can I protect an already encrypted PDF?
Unlock it with the known password first, then create a new protected copy.