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PDF Locker

PDF Security Tool

PDF Locker

Add password protection to your PDF files. Secure invoices, contracts, and private documents with strong encryption — all in your browser.

Password Protection 100% Private Instant Always Free

Protect PDF with Password

Drop your PDF here

Drag & drop or click to browse · PDF only · Max 20 MB

Choose File

PDF

Your PDF and password never leave your device. All encryption happens locally in your browser.

Use Cases

Contracts & Agreements

Add access control before sending drafts

Finance & Invoices

Share bills and statements more safely

Sensitive Documents

Secure copies before external sharing

How to Use

Upload PDF

Select your PDF file

Enter Password

Type a strong password (6+ characters)

Lock & Download

Click Lock and save your protected PDF

Password Tips

Use 8+ characters

Longer passwords are more secure

Mix character types

Upper, lower, numbers, symbols

Don't reuse passwords

Use unique passwords for each PDF

Why Lock Your PDF?

Secure Sharing

Control who can open your PDF

Legal Compliance

Meet data protection requirements

Safe Email Attachments

Send sensitive files with confidence

Cloud Storage Security

Extra layer for stored documents

Frequently Asked Questions

Does this change the original PDF?

No. The tool creates a protected copy and leaves your original file unchanged. You'll download a new locked PDF.

Is the lock added in my browser?

Yes. Your PDF is processed locally using pdf-lib. The file and password never leave your device.

Should I use a strong password?

Yes. Use at least 8 characters with a mix of letters, numbers, and symbols for better protection.

Can I remove the password later?

Yes. If you know the password, use the PDF Unlocker tool to export an unlocked copy.

What encryption is used?

PDF 2.0 encryption with 128-bit AES. This is the standard for PDF password protection.

Is there a file size limit?

Maximum 20 MB per file. Most PDFs are well within this limit.

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