Password Protect PDF Free Online
Add a password to any PDF directly in your browser. Your file is encrypted locally — nothing is ever uploaded to a server. Free, instant, and completely private.
Password protect PDFs
Add a PDF open password locally in your browser. Your file and password never upload to a server.
Why Password-Protect a PDF?
Sensitive documents — tax returns, legal agreements, medical records, financial reports, and personal identification — deserve protection before being shared digitally. Adding a password to a PDF ensures that only the intended recipient can open and read it. Even if the file is intercepted or forwarded by mistake, it remains unreadable without the password.
How it works: Our tool applies AES-based PDF encryption directly in your browser. You choose a password, and the tool re-packages the PDF with that password embedded as an open restriction. Anyone who tries to open the file will be prompted for the password before the content is displayed.
Privacy-first encryption: Your PDF is never sent to any server. All encryption runs locally using WebAssembly in your browser. This means your confidential document never leaves your device, regardless of how sensitive the content is.
Removing a password: You can also use this tool to remove an existing password from a PDF you own. Simply upload the file, enter the current password, and download the unlocked version. Useful for PDFs you need to compress, sign, or merge after removing their password restriction.
Tips for strong passwords: Use a mix of uppercase and lowercase letters, numbers, and special characters. Avoid using names, birthdays, or common words. Share the password via a separate communication channel (e.g., phone call or encrypted message) rather than including it in the same email as the PDF.
When to Use PDF Password Protection
Legal & Finance Documents
Protect contracts, tax filings, balance sheets, and bank statements before emailing to clients, accountants, or lawyers. Prevent unauthorized access if email is compromised.
HR & Employment Records
Password-protect offer letters, payslips, performance reviews, and identity documents shared during onboarding. Keep employee data confidential even if forwarded.
Medical & Health Records
Secure lab results, prescriptions, and insurance documents before sending via email or messaging apps. Ensure only the intended recipient can access your health data.
Creative & Business Work
Protect unreleased designs, proposals, and business plans shared with potential clients or partners. Add a password layer before distributing drafts or proprietary content.
Frequently Asked Questions
Is the encryption strong enough for sensitive documents?
Yes. The tool applies AES-128 or AES-256 encryption depending on the PDF version used. This is the same encryption standard used by financial institutions and government agencies. The security of the protection depends entirely on the strength of your chosen password.
Is my PDF uploaded to your servers?
No. Your PDF is processed entirely in your browser using WebAssembly. No file data is ever transmitted to our servers. Your document and password remain private on your device throughout the process.
Can I remove a password I previously added?
Yes. Upload the protected PDF, enter the correct password, and choose the remove option to download an unlocked version. You must know the current password to remove it.
Will the protected PDF open on any device?
Yes. Password-protected PDFs are a standard feature supported by all major PDF viewers including Adobe Acrobat, Preview on Mac, Chrome, Firefox, Edge, and mobile PDF readers on iOS and Android.
What happens if I forget the password?
If you forget the password, you will not be able to open the file. We do not store your password anywhere. Always keep a backup of the original unprotected file and store the password in a secure password manager.