Lock PDF with a password
Add a password to any PDF with AES-256 encryption — free, private, and processed entirely in your browser. No uploads, no account.
3M+
PDFs locked
AES-256
Encryption standard
<2s
Average lock time
0
Files ever uploaded
How to password protect a PDF online
Three steps, no account, no upload — locked in under five seconds.
Select your PDF
Drop a file or click to browse. Works on phone, tablet, and desktop — no app to install.
Set a password
Choose a password in the editor. Encryption runs instantly in your browser, no server involved.
Download your locked PDF
Save the password-protected PDF instantly. No watermarks, no email, no waiting.
Everything you need to password protect PDFs
A complete, free PDF locker that works in any browser — no software to download, no account to create.
AES-256 encryption
Your PDF is locked with industry-standard AES-256 password encryption — the same strength used by banks and government agencies.
Works on every device
Password-protect PDFs on Windows, Mac, Linux, iPhone, and Android. Any modern browser works — no app install required.
No watermarks
Your locked PDF comes out clean — no logos, no stamps, no added pages. Only a password is added, nothing else changes.
100% private & secure
Encryption happens locally in your browser and your file is never uploaded. Nothing touches a server — not even the password.
Lightning fast
No upload and download round-trip means your PDF is locked instantly, even on slow connections.
Free & unlimited
Lock as many PDFs as you want, as often as you want. No signup, no free-trial countdown, no hidden paywall.
Bank-grade encryption, not just a password prompt
We apply real AES-256 encryption to the PDF itself, so the file can't be opened without the password — not a flimsy wrapper.
Your files and password never leave your device
Locking runs fully client-side in your browser. Nothing is sent to a server, nothing is stored — not your file, not your password.
What people lock PDFs for
A password stops the wrong person from opening a file. Here's where it matters most.
Protect financial statements
Add a password to bank statements, tax returns, and invoices before emailing them to accountants or clients.
Secure HR & legal documents
Lock contracts, offer letters, and personnel files so only the intended recipient can open them.
Share medical records safely
Password-protect lab results and health records before sending them over email or shared drives.
Guard confidential reports
Restrict access to internal reports, board decks, and strategy documents before distributing them.
Send client deliverables privately
Lock proposals, invoices, and deliverables so only the paying client can open the file.
Protect personal documents
Add a password to IDs, passports, and other sensitive scans before storing or sharing them online.
More free PDF tools
Everything runs in your browser — private, free, and no signup, just like the locker.
Trusted by accountants, HR teams & clinics
Thousands of people lock PDFs here every day. Here's what a few of them say.
“I lock every client invoice before emailing it. Takes seconds and nothing ever leaves my laptop — exactly what I needed.”
“We password-protect every contract before it goes out for signature. This tool made that a one-click step.”
“Sending lab results to patients used to worry me. Now every file is encrypted locally before it leaves my machine.”
Frequently asked questions about locking PDFs
What encryption is used to lock my PDF?
We use AES-256 encryption, the same standard used by banks and government agencies, so your locked PDF can't be opened without the password.
Do my files get uploaded to a server?
Never. Locking happens locally in your browser using JavaScript. Your file and password never leave your device.
Will the locked PDF have a watermark?
No watermarks, stamps, or added pages — ever. The output is your original PDF with a password added, nothing else changes.
Can I lock PDFs on my phone?
Yes. The tool works on any device with a modern browser — iPhone, Android, tablet, or desktop. No app download needed.
What if I forget the password I set?
We don't store your password, so we can't recover it for you. Keep it somewhere safe — without it, the PDF can't be opened.