Protect PDF — Add Strong Password & Client-Side Encryption
MakeCard PDF Lock is a client-side document security tool that enables you to protect sensitive PDF files with password encryption directly inside your web browser. In an era of rampant data breaches and unauthorized forwarding of confidential documents, encrypting personal IDs, business proposals, contracts, legal agreements, and financial records ensures that only recipients possessing the correct secret passphrase can open and view the file.
How to Use PDF Lock
Select the PDF file you wish to encrypt by dragging it into the dropzone or clicking "Choose PDF File".
Type your chosen strong password in the "New Password" input field.
Confirm the password in the second field to prevent typographical errors.
Click "Protect & Download PDF" to encrypt the document locally using the PDF-Lib cryptographic engine.
Download your encrypted PDF. When opened in any PDF viewer (Adobe Acrobat, Chrome, Preview), it will demand the password.
Key Features & Capabilities
- 100% In-Browser Encryption: Your unencrypted document never leaves your machine or phone.
- Standard Multi-Platform Compatibility: Encrypted PDFs open seamlessly on Windows, macOS, iOS, Android, and Linux.
- Double Password Confirmation: Eliminates accidental typos that could lock you out of your document.
- Fast local processing: Encrypts documents within seconds using local CPU execution.
- Zero file storage: Once downloaded, document data is purged from temporary browser memory.
Supported Formats & Specifications
| Parameter | Specification |
|---|---|
| Supported Input | Standard .pdf documents (scanned or text-based) |
| Encryption Type | Standard PDF Security handler compatible with all standard viewers |
| Password Support | Letters, numbers, and special symbols (!@#$%^&*) |
| Server Upload | 0 KB — Completely private and offline-capable |
| Output | Encrypted .pdf file prefixed with "protected-" |
Practical Everyday Use Cases
- Securing salary slips, bank statements, and tax returns before emailing them to banks or consultants.
- Protecting business price quotations, NDA agreements, contracts, and confidential proposals.
- Encrypting personal identification scans (Aadhaar, PAN, Passport) before sending them over WhatsApp or email.
- Restricting unauthorized access to confidential school examination question papers and legal case briefs.
Pro Tips for Best Results
- Use a password combining uppercase letters, lowercase letters, numbers, and symbols for robust security.
- Store your password securely; because MakeCard does not store your files or passwords on a server, lost passwords cannot be retrieved.
- Share the password with the recipient through a separate communication channel (e.g. SMS/call) rather than in the same email containing the attached file.
Common Problems & Solutions
Privacy & Security
100% Client-Side In-Browser Execution
Encryption is performed client-side using JavaScript in your web browser. MakeCard has no access to your document contents or the password you set.
Frequently Asked Questions
Everything you need to know about using the PDF Lock