Protect PDF
Add password protection to your PDF files. AES-256 encryption, 100% in your browser.
Add password protection and AES-256 encryption to your PDF files. This prevents unauthorized users from opening, copying, or printing your sensitive documents. Essential for contracts, financial reports, medical records, and any confidential material shared digitally.
You set the password, and the tool encrypts the entire document in your browser. The encrypted PDF can only be opened by someone who knows the password. Since encryption happens client-side, your unprotected document is never sent to any server.
Drop your PDF file here to protect
or click to browse
Frequently Asked Questions
How to Password Protect a PDF
Add AES-256 encryption and a password to any PDF. This prevents unauthorised access — the recipient must enter the correct password to open and view the document. Essential for contracts, financial statements, medical records, and any sensitive information.
- Upload the PDF you want to protect.
- Enter a strong password (we recommend 8+ characters with mixed case, numbers, and symbols).
- Click "Protect PDF" to encrypt the file.
- Download your secured PDF and share it safely.
Unlike many "PDF protectors" that only add permission flags (which are trivially bypassed), Tiny PDF Tools applies genuine AES-256 encryption — the same standard used by banks and government agencies. Once protected, the document simply will not open without the correct password.
Why AES-256 matters - It is approved for TOP SECRET data by the NSA and is the industry standard for strong encryption. - With 2^256 possible keys, brute-forcing a strong password is computationally infeasible. - Any standard reader (Adobe, Chrome, Preview) can open an AES-256 PDF once the password is entered.
Documents worth encrypting - Financial statements, tax returns, and pay stubs before emailing them. - Medical records, legal filings, and signed contracts shared with third parties. - Any file you are sending over email or chat where interception is a concern.
Share the password safely Because encryption runs entirely in your browser, your password is never transmitted anywhere — which also means we cannot recover your file if you forget it. Choose a strong password, and always send it to your recipient through a separate channel (a phone call or text), never in the same email as the file.
Frequently Asked Questions
How do I password protect a PDF for free?
Upload your document to our tool, type a secure password, and click protect. The tool downloads a new, encrypted copy of your PDF without charging any fees.
Can someone brute-force the PDF password?
With AES-256 encryption, brute-forcing a strong password (8+ mixed characters) would take modern supercomputers millions of years. A weak password like "1234" can be guessed, so always choose a complex one.
Is it safe to encrypt financial records online?
Yes, but only if processing is 100% client-side. TinyPDFTools never uploads your file, so your financial records are never exposed to the internet.
Can I lock a PDF from being printed or copied?
Currently the tool applies an "open" password that locks the whole document from being viewed without the password. Granular permission controls (like disabling printing) are planned for a future update.
What happens if I forget the password?
We cannot recover it. Because encryption is done locally and the password is never stored or sent to us, a forgotten password means the file cannot be opened — so keep an unencrypted backup in a safe place.