Password Protect PDF
Add a password to your PDF so it cannot be opened without it, right in your browser. Set your password, confirm it, and download the protected file. Need to remove a password you own instead? Use our unlock PDF tool, or shrink the file first with the PDF compressor.
Password Protect PDF
Upload a PDF, set and confirm a password, then encrypt it in your browser
What is PDF Password Protection?
PDF password protection adds an open password to a PDF (Portable Document Format) file so it can only be viewed by someone who knows that password. When a protected file is opened, the PDF reader prompts for the password before showing any content. According to MDN Web Docs, a PDF is a self-contained document format, and the standard supports encrypting its contents so the file stays unreadable without the correct password.
This tool applies standard AES encryption, the same open password mechanism that PDF viewers understand. It is useful for sharing sensitive contracts, invoices, financial statements, and personal records, since the file requires the password to open no matter where it is stored or sent. It is not a digital certificate and not a legally binding signature. It is a password that controls who can open the document.
This tool uses @cantoo/pdf-lib, a fork of the popular pdf-lib JavaScript library that adds real AES password encryption, to protect your file entirely in your browser. Because the work happens locally, we never see or store your password or your file. If you later need to remove a password from a file you own, use our Unlock PDF tool.
✗Before Protection
An unprotected PDF opens instantly for anyone who has the file. There is nothing stopping a person who receives or finds it from reading every page.
document.pdf
Opens without a password
✓After Protection
The file is encrypted with the password you chose. Every time the PDF is opened, the reader asks for that password before showing any content.
protected-document.pdf
Requires the password to open
Why Use This Password Protect Tool?
Adding a password keeps sensitive PDFs private when you store or share them. Here are the key advantages of using this browser-based tool:
Lock Sensitive Files
Require a password to open contracts, financial statements, medical records, and other private documents. Only people you share the password with can read the file.
Password Never Leaves Your Browser
Both the PDF and the password are handled entirely on your device with client-side JavaScript. Nothing is uploaded, and we never see or store the password you choose.
Standard PDF Encryption
The tool applies AES encryption using the standard PDF open password. Any compliant PDF reader will recognize it and prompt for the password before opening the document.
Confirm to Avoid Typos
A confirm field checks that both password entries match before the file is encrypted. This helps you avoid locking a document with a password that has a typo in it.
Fast and Free
Client-side processing means instant results with no file uploads and no waiting on a server. Protect documents in seconds, at no cost, with no account and no limits on how many files you process.
Works on Any PDF
Protect a one-page form or a hundred-page report with the same simple steps. The password applies to the whole document, so every page is covered at once.
How It Works
This tool uses @cantoo/pdf-lib to encrypt your PDF directly in your browser. Here is how the process works:
Upload PDF File
Upload your PDF file. The tool loads it in your browser and displays the number of pages so you know which document you are about to protect.
Set and Confirm Password
Type the password you want, then confirm it by typing it again. The tool checks that both entries match and are at least 4 characters long.
Protect and Download
Click Protect PDF to encrypt the file in your browser. Once processing finishes, download your password protected PDF file.
Best Practices for Password Protection
To keep your protected PDFs both secure and usable, follow these best practices:
- ✓Choose a strong password: Use a mix of letters, numbers, and symbols that is hard to guess. A longer password is harder to break than a short one.
- ✓Confirm the password carefully: Double check the confirm field so you do not lock a file with a password that has a typo. You will need the exact password to open it later.
- ✓Store the password somewhere safe: Because everything runs in your browser, we never see or store your password, and there is no way to recover it. A password manager is a good place to keep it.
- ✓Keep a backup of the original: Save your original, unprotected file in a safe place in case you ever lose the password or need a clean copy.
- ✓Share the password separately: Send the protected file and its password through different channels, for example the file by email and the password by message, so a single leak does not expose both.
- ✓Remove protection when you own the file: If you have the password and want an unprotected copy, use the Unlock PDF tool to reverse this step.
Frequently Asked Questions
How do I password protect a PDF?
Upload your PDF file, type the password you want to set, confirm it by typing it again, then click Protect PDF. The tool encrypts the file in your browser so it can only be opened with that password. When it finishes, download your protected PDF.
Is this password protect tool free?
Yes, this tool is 100% free. There is no registration, no account, and no hidden fees. All processing happens in your browser, so your file and your password never leave your device and stay completely private.
Does my PDF or password get uploaded to a server?
No. Everything runs locally in your browser using client-side JavaScript. Your PDF is never uploaded, and your password is never sent anywhere or stored. This matters most for the password, since we never see it or keep a copy.
What kind of encryption does this use?
This tool applies standard PDF password encryption using AES, the same kind of open password that PDF readers prompt for when you open a file. Anyone who wants to open the document will need to enter the password you set. It is not a digital certificate and not a legally binding signature.
How do I remove a password from a PDF?
If you own the file and know its password, you can remove it with our Unlock PDF tool. This tool adds an open password to a PDF, and unlocking reverses that step when you have the correct password.
What happens if I forget the password?
There is no recovery option. Because the tool runs entirely in your browser, we never see or store your password, so we cannot reset it for you. Keep a safe record of the password you choose, and always keep a backup of your original, unprotected file.
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