Password Protect PDF with 256-Bit AES
Add a password to PDF online free — lock, encrypt and secure PDFs with user and owner passwords, and restrict printing, copying and editing. No upload, no signup, 100% in-browser.
Drop your PDF here
or press Ctrl+V to paste
or
🔒 Secure - processed locally in your browser, never stored or reused.
100% Private
Everything runs in your browser. No files are uploaded to any server.
Strong Encryption
Up to 256-bit AES encryption, matched to your file's PDF version.
User + Owner Passwords
Set an open password plus a separate permissions password.
Print, Copy & Edit Control
Control printing, copying, and editing with granular permissions.
How to Protect PDF Files
Step 1
Upload PDF File
Drag and drop your PDF document into the upload dropzone or select from your device.
Step 2
Set Password & Permissions
Enter a strong password and choose permissions (prevent printing, editing, or copying).
Step 3
Encrypt & Download
Click Protect PDF to apply strong encryption (up to 256-bit AES) instantly in your browser, then download.
When to Use This Tool
Client Deliverables
Password-protect contracts, invoices, and proposals before sending to clients.
Sensitive Documents
Secure medical records, financial statements, and legal papers with password protection.
Academic Submissions
Protect research papers and thesis documents before sharing with reviewers.
Internal Reports
Restrict access to confidential business reports and strategy documents.
AFFLIGO Protect vs Smallpdf & Adobe
AFFLIGO
- ✓True AES-256 via QPDF
- ✓Owner + user passwords
- ✓Print/copy/edit permissions
- ✓Batch queue, device-adaptive limits
Smallpdf
- ✗Files upload to encrypt
- ✗Advanced password options need Pro
- ✗Permission control needs Pro
- ✗Free tier ~5MB cap
Adobe
- ✗Encrypt runs in cloud
- ✗Passwords need Acrobat Pro
- ✗Granular permissions need Pro
- ✗File-size caps apply
Frequently Asked Questions
Yes. All processing happens directly in your browser using the local encryption engine (QPDF compiled to WebAssembly, with pdf-lib fallback). No files are ever uploaded to any server.
A user password is required to open the PDF. An owner password controls permissions like printing, copying, and editing. You can set either or both.
Yes. Use the permission checkboxes to independently control printing, copying, and editing permissions on the protected PDF.
Limits adapt to your device - the dropzone shows your exact per-file limit. Encryption is fast since it happens entirely in your browser with no upload required.
The tool applies strong standards-based PDF encryption (up to 256-bit AES, matched to your file's PDF version) entirely in your browser. Your file never leaves your device.
Yes. Enter the existing password when prompted, then set a new password. You can change or strengthen protection at any time. Need to remove protection entirely? Use our Unlock PDF tool.
Yes. Mac Preview and Microsoft Word export apply AES-128 encryption, while this tool applies true 256-bit AES via QPDF — a substantially larger key space with more cryptographic margin for sensitive documents.
Yes. Open this page in Safari on your iPhone or iPad — no app download needed. Add the PDF from the Files app, set your password and permissions, then save the protected file back to Files. Everything runs locally in Safari.