Encrypt PDF
Runs locally in your browser. Nothing leaves your device.Protect PDF files directly in your browser with AES-256 encryption, no upload, and optional permissions.
How it works
- 1
Add PDF files
Select up to 20 local PDF files, each up to 250 MB, up to 500 MB total.
- 2
Set the password and mode
Set an opening password and choose between Simple and Advanced mode with permissions.
- 3
Download the encrypted PDFs
Download the encrypted PDF directly, or multiple results bundled as a ZIP.
Good to know
The PDF encryptor protects PDF files with AES-256 encryption directly in your browser. Simple mode needs only an opening password with an automatically generated, unstored owner password; Advanced mode allows a custom owner password and granular restrictions on printing, editing, and copying.
A strength indicator recommends at least 16 characters without reuse. Important: permissions such as print or copy restrictions are not DRM and can be ignored by non-compliant software. Encrypted PDFs are also not PDF/A compliant, and existing digital signatures become cryptographically invalid.
Typical use cases
Quickly protect confidential documents with a password
Use Simple mode for an opening password when you don't need granular restrictions — all normal PDF functions remain allowed.
Selectively restrict printing or editing
Switch to Advanced mode to limit printing to low resolution, or to individually allow or block editing, annotating, and copying.
Tips for better results
Use a strong, unique password
Use at least 16 characters and a password you haven't reused elsewhere — a forgotten opening password cannot be recovered reliably.
Check PDF/A and signatures before encrypting
If PDF/A compliance or valid digital signatures matter, encrypt only after completing all archiving or signing steps.
Features
AES-256 encryption
Each source becomes a new AES-256 encrypted PDF file, locally.
Simple and Advanced modes
Choose a single opening password or granular permissions for printing, editing, and copying.
Password strength indicator
A strength indicator (weak/medium/strong) helps you choose a sufficiently secure password.
Frequently asked questions
Are permissions like a copy restriction secure?
No. Permissions are evaluated by PDF readers, but they are not DRM and can be ignored by some software.
Does a digital signature stay valid after encryption?
No. Encryption creates a new PDF file; existing digital signatures become cryptographically invalid.
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