Add password protection to any file with AES-256 encryption — processed entirely in your browser. No uploads. No servers. Your data never leaves your device.
Protect a File NowSelect any file, set a strong password, and encrypt it securely with AES-256-GCM — all in your browser.
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Any file type • Max 1GB • Processed locallyThree simple steps to secure your documents
Choose any file — PDF, Word, images, videos, or archives. It stays on your device the entire time.
Enter your own password (12+ characters) or let UniDoc auto-generate a cryptographically secure one for you.
Your file is encrypted with AES-256 and ready to download. Decrypt anytime with the same password.
The most secure way to password protect files online
Your file never leaves your device. All password protection and encryption run locally in your browser using the Web Crypto API.
Unlike server-based tools, your file is never sent anywhere. Zero-knowledge architecture ensures complete privacy.
Military-grade authenticated encryption with 150,000+ PBKDF2 iterations. The same standard trusted by governments worldwide.
Your password-protected file is ready to download immediately. No waiting, no queues, no email required.
Once the page is loaded, the file encryption tool works entirely offline. Disconnect from the internet and keep protecting files.
Files protected here use the same .ufenc format as the UniDoc app. Encrypt on web, decrypt on mobile — and vice versa.
Most online tools that claim to password protect PDF or secure file online actually upload your document to their servers — exposing your private data to potential breaches. UniDoc is different.
Our browser-based file security tool uses the Web Crypto API to encrypt file in browser with AES-256-GCM, the same standard used by military and financial institutions. Your file never leaves your device — not even for a millisecond.
Whether you need to protect document with password before sharing, add file protection to sensitive PDFs, or use a reliable file encryption tool, UniDoc delivers enterprise-grade security with zero-knowledge architecture. No accounts, no uploads, no compromises.
No. Your file is never uploaded anywhere. All password protection and encryption happen locally in your browser using the Web Crypto API. Your data never leaves your device.
UniDoc uses AES-256-GCM encryption with PBKDF2-SHA256 key derivation (150,000+ iterations). This is the same military-grade standard used by governments and financial institutions.
Yes. You can decrypt your password-protected .ufenc file anytime using the UniDoc Encrypt tool or the UniDoc mobile app. Just provide the same password you used during encryption.
Yes, completely free with no registration required. For advanced features like vault storage, biometric lock, and QR code key sharing, download the UniDoc app.
Yes. Once the page is loaded, all encryption operations run entirely in your browser using JavaScript. You can disconnect from the internet and the tool will continue to work.
Any file type — PDF, Word, Excel, images, videos, archives, and more. The tool works with any file up to 1 GB.
Yes. Files encrypted here use the exact same .ufenc format as the UniDoc mobile app. You can encrypt on the web and decrypt on your phone, or vice versa.
Password protect any file for free — right in your browser. No uploads, no sign-ups, no compromises.