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Protect PDF

Add a password to your PDF

About this tool

Add real AES password encryption to your PDF, entirely in your browser. The output works with Adobe Acrobat, Chrome's built-in PDF viewer, Firefox, Preview on Mac, and other standards-compliant readers. Optionally restrict copying, editing, and annotation while still allowing printing. Files are processed locally — your password and PDF never leave your device.

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By Dakshesh · Web Engineer & SEO Specialist · Last updated 2026-05-09

Why use a protect pdf tool?

Sensitive PDFs — contracts, ID copies, financial statements — should never travel without encryption. Adding a password ensures only intended recipients can open the file. ShrinkTo applies AES encryption locally so even we never see your password or content.

Common use cases

Send contracts safely

Encrypted PDF over email is far safer than plain attachments.

Protect ID documents

Aadhaar/PAN scans should always have a password if shared.

Financial reports

Salary slips, bank statements protected with a unique password.

Confidential proposals

Client-only access with a shared password.

How to password-protect a PDF

Upload PDF. Drop the file you want to protect.
Set password. Choose something strong — at least 12 characters mixing letters, numbers, symbols.
Click Protect. AES encryption applied locally.
Download protected PDF. File now requires the password to open.

Frequently asked questions

What encryption is used?

AES-256 — the same standard banks and governments use.

Can I recover a lost password?

No. There is no backdoor by design. Save the password somewhere safe.

Will all PDF readers prompt for password?

Yes — every standards-compliant PDF reader handles encryption properly.

Does encryption affect printing?

By default protected PDFs allow printing. You can also disable printing, copying, or editing.

Does this prevent screenshots?

No. PDF encryption protects the file. Screenshots are an OS-level activity beyond any document's control.

verified

Privacy by design.

All processing happens in your browser using JavaScript libraries. Your files never reach any server. No accounts, no tracking, no data retention.