Password Protect a PDF
Encrypt a PDF with a password using AES-256 or AES-128. The result is verified by re-opening it with an independent reader before you download — all in your browser.
Encryption runs on the AES implementation inside the library this tool uses, in your browser. No strength claim beyond the selected standard (AES-256 or AES-128) is made here, and nobody can recover a forgotten password.
How to use
The whole flow runs in your browser — nothing is uploaded.
- UploadAdd the PDF you want to lock.
- Choose a passwordType the password you will need to open the file, and confirm it. Use the Show button to check it.
- Pick the encryptionAES-256 by default, or AES-128 if you must support a very old viewer.
- Protect and verifyPress Protect PDF; the result is re-opened to confirm it really demands the password.
- DownloadSave the protected PDF and keep the password safe.
- Every step runs locally in your browser.
Key Features
AES-256 or AES-128 encryption, applied in your browser — and the result is re-opened to prove the password is really required.
- A real opening passwordThe output genuinely requires the password before any page can be read.
- Verified before downloadThe result is re-opened with an independent reader to prove it locks, unlocks and rejects a wrong password.
- AES-256 or AES-128Current standard encryption by default, with the older handler available for legacy viewers.
- Optional owner passwordSet a second, full-access password, or let the opening password act as both.
Frequently asked questions
Yes, and the tool proves it rather than asking you to take its word for it. After encrypting, the file is re-opened with an independent PDF reader: it must refuse to open without a password, open with the password you set, and reject a wrong password. All three results are shown before you download.
No. The password stays in this browser tab and is used only to encrypt the document you selected. It is never written to a URL, local storage, analytics or a log, and this tool cannot recover it for you.
No — and nobody else can either. The password is not stored in the file in any form that can be reversed. Keep it somewhere safe before you download.
Not directly. Encrypting an encrypted document without its password is not something this tool can do honestly, so it asks you to unlock the file first — then you can set a new password here.