Password Protect a PDF — Free & Private
Encrypt a PDF with a password using strong AES-256 encryption, right in your browser. Your confidential file is never uploaded. No accounts, no watermarks, no limits.
🔒 Protect a PDF now →How to password protect a PDF for free
- Open the Moriaki PDF protect tool in your browser.
- Drag and drop the PDF you want to secure.
- Enter the password you want to require to open the file.
- Click Protect and download the encrypted PDF. Your file never leaves your device.
Why password protect PDFs with Moriaki?
Encrypting a sensitive document on a website that first uploads it to a server defeats the purpose. Moriaki applies AES-256 encryption locally in your browser, so the unprotected file and your password never leave your device.
The result is a properly encrypted PDF that asks for your password to open — with no watermark, no account, and no file size games.
Encryption is most useful for documents that move between people. Accountants sending returns to clients, HR teams sharing payslips, clinics emailing results and freelancers sending signed contracts all benefit from a file that stays locked if it is forwarded by mistake. Pair it with a sensible habit: agree on how the key will be shared before you send anything, and never write it in the email subject or body. For very sensitive paperwork, use a fresh, unique passphrase for each recipient, so one shared key never unlocks everything you have sent.
Frequently asked questions
Is password protecting a PDF free?
Yes — free, with no account, no limits, and no watermark.
Is my file or password uploaded?
No. Encryption runs entirely in your browser; neither the file nor the password is ever sent to a server.
How strong is the encryption?
It uses AES-256, the same strong standard used to secure sensitive documents.
What happens if I forget the password?
The PDF cannot be opened without it, and we cannot recover it — there is no copy anywhere. Store your password safely.
Does it work on mobile?
Yes — in any modern browser, with no app needed.
How to password protect a PDF without uploading it
Add your file
Drop it in. The document opens inside your browser and is never sent to a server.
Set a password
Choose a strong one — it becomes the key that unlocks the document.
Download
Save the encrypted copy. Your original stays untouched on your device.
Tax returns, payslips, medical letters, contracts and ID scans all travel by email every day. Locking them with a password adds protection that goes with the file: even if a message is forwarded or lands on the wrong device, nobody can open it without the key. The irony is that most online tools ask you to upload the unprotected document first. Here you can password protect a PDF entirely in your browser, so the readable version never leaves your computer.
What the encryption actually does
A password here isn’t just a prompt sitting in front of readable content. The text and images themselves are scrambled with AES-256, the same standard used for banking and secure messaging, so without the key the file is unreadable data. The number of possible keys is so large that guessing them by brute force isn’t realistic — which means the strength of your protection really comes down to the password you choose.
Choosing a password that holds up
- Go long. A passphrase of four or five random words beats a short string of symbols.
- Don’t reuse one you already use for an email or bank account.
- Send it separately. If you email the document, share the key by text or phone, not in the same message.
- Keep a safe copy. Real encryption has no back door — a lost key can’t be recovered by anyone, including us.
Moriaki vs. typical online tools
| Moriaki | Typical online tools | |
|---|---|---|
| Unprotected file uploaded to a server | Never | Usually yes |
| Your password sent to a server | Never | Often |
| Account required | No | Often |
| Encryption strength | AES-256 | Varies |
| Works offline | Yes | No |
| Price | Free | Free / freemium |
The result is a standard document format file that opens in any normal reader — Adobe Reader, Preview, Chrome or Edge — which simply asks for the password before showing the contents.
Password protect PDF — frequently asked questions
Is it free?
Are my file and password uploaded anywhere?
What if I forget the password?
Will the recipient need special software?
Does it change my original?
Can I use it on my phone?
