Online PDF Encryption Tool
Add password protection to PDF files for free. Supports open password and permission password. Local encryption, no server upload.
How to Use
Select file
Start process
Local processing
Download result
Complete PDF Encryption Guide
Encryption Features
The PDF encryption tool adds password protection using AES-256 encryption — entirely processed locally in your browser. Your files and passwords never leave your device. Two passwords are used: 1) Open password (user password, required, at least 4 characters) — needed to view the file; 2) Owner password (optional) — governs the printing, copying, editing and annotation permissions you choose; if left blank, a random one is generated. Files that are already encrypted and PDF/A files are rejected. Encrypted PDFs open in common PDF readers once the password is entered.
Processing Results
Technical Specifications
Feature Comparison
| Feature | Allin PDF | Other Tools |
|---|---|---|
| Encryption | AES-256 | Varies by tool |
| File and password | Stay in your browser, never uploaded | Many online tools upload files to their servers |
| Permissions | Print, copy, edit, annotate | Varies by tool |
Key Facts
Allin PDF encrypts PDFs with AES-256; an open password of at least 4 characters is required.
The owner password is optional, and Allin PDF generates a random one if you leave it blank; printing, copying, editing and annotating can each be allowed or blocked.
Allin PDF encrypts in your browser with @cantoo/pdf-lib, so neither the PDF nor the password is uploaded, and no sign-up is needed.
Already-encrypted PDFs and PDF/A files are rejected; one file is processed at a time and saved with an _encrypted suffix.
Privacy Protection
This tool processes your files in your browser: they are not uploaded to a server, and no sign-up or login is needed.
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FAQ
What encryption standard does Allin PDF use?
Allin PDF uses AES-256 encryption. The encrypted PDF requires the open password (at least 4 characters) to view, and you choose which actions remain allowed: printing, copying, modifying and annotating. An optional owner password controls these permissions; if left blank, a random one is generated.
Is PDF encryption done locally?
Yes, completely local. The encryption is applied in your browser using @cantoo/pdf-lib. Your password and file are never sent to any server.
Can I remove encryption from a PDF?
Yes, if you know the password. The Unlock PDF tool in the Allin PDF web app removes the open password and editing restrictions in your browser; either the user or the owner password works. It cannot recover or bypass a password you do not know. The encrypt tool itself rejects files that are already encrypted.
Process Documents Anywhere
Download the Allin PDF iOS app. Its local tools also work offline.