Encrypt any file with military-grade AES-256-GCM directly in your browser. PBKDF2 key derivation, password protection, and zero server uploads — your files never leave your device.
100% In-Browser Cryptography.
Zero bytes of your files or passwords are ever sent to any remote server. Encryption uses native W3C WebCrypto API directly on your CPU.
Drop any file here or click to browse
PDF, Images, ZIP, Office docs, Videos — any binary format supported
Enter a password to protect your file.
AES-256-GCM Authenticated Encryption
Provides both confidentiality and integrity. Any bit-flip or corrupted byte causes decryption to instantly reject.
PBKDF2 (210,000 Iterations)
Slows down GPU/ASIC brute-force attempts. A weak password is still vulnerable — check the strength meter.
Zero Backdoors & Unrecoverable
No master key or reset option exists. If you lose your password, the encrypted data is permanently lost.
Native WebCrypto in Secure Context
Executes locally via your browser's crypto.subtle in HTTPS. 0 bytes ever leave your device or enter server logs.
Geek check: open DevTools → Network tab — 0 bytes of your data uploaded.
Cloud storage providers like Google Drive, Dropbox, iCloud, and OneDrive are convenient, but they hold the encryption keys to your data. Whether through government subpoenas, accidental insider leaks, account takeovers, or cloud misconfigurations, unencrypted files stored online are inherently vulnerable.
Similarly, when sending confidential contracts, tax returns, source code, medical records, or cryptocurrency seed backups via email, Slack, Teams, or messaging apps, your files traverse third-party mail servers and caching proxies in plaintext. Encrypting your files client-side with a strong password before uploading or transmitting ensures true end-to-end confidentiality: even if the transmission channel or storage bucket is compromised, an attacker sees only indistinguishable random noise.
Many legacy encryption tools rely on CBC (Cipher Block Chaining) or unauthenticated CTR modes, which only scramble content but cannot detect whether an attacker flipped bits in transit. YuliusBox File Encryptor utilizes AES-256-GCM (Galois/Counter Mode). GCM computes a cryptographic 128-bit authentication tag alongside the ciphertext.
If even a single byte of the encrypted file is altered, corrupted, or replaced, the WebCrypto engine rejects decryption immediately. This guarantees both complete confidentiality and cryptographic data integrity.
Humans remember passwords, not 256-bit cryptographic keys. Converting a password into an encryption key requires a deliberately slow key-stretching algorithm to thwart offline dictionary and brute-force attacks.
We apply PBKDF2 using HMAC-SHA-256 with 210,000 iterations and a unique 16-byte cryptographically secure random salt for every file. This means an adversary attempting to crack your password with high-end GPUs must compute 210,000 SHA-256 rounds for every single password guess. Use the built-in password strength meter to choose a passphrase of 12+ characters for maximum security.
This tool uses industry-standard AES-256-GCM (Galois/Counter Mode) authenticated encryption. Your password is never used directly as the cryptographic key; instead, a 256-bit AES key is derived using PBKDF2 (Password-Based Key Derivation Function 2) with SHA-256, a cryptographically secure 16-byte random salt, and 210,000 iterations (following modern OWASP recommendations). Each file encryption generates a fresh 12-byte initialization vector (IV / 96-bit nonce). All cryptography runs directly inside your browser via the standard W3C Web Cryptography API (crypto.subtle).
No. Recovery is mathematically impossible. This tool operates under a strict zero-knowledge, zero-backdoor model. There are no master keys, no recovery questions, no escrow, and no copies of your password or files sent anywhere. If you forget or lose the password, the encrypted .enc file cannot be decrypted by anyone in the world.
No, never. 0 bytes of your files or passwords ever leave your computer. Both encryption and decryption occur entirely within your web browser using client-side JavaScript and HTML5 File APIs. You can even load this page, disconnect your Wi-Fi or enable Airplane mode, and encrypt or decrypt your files completely offline.
Yes. You can decrypt your .enc file on any device (Mac, Windows, Linux, iOS, Android) by opening this tool in any modern web browser and entering the correct password. Furthermore, because the binary format is completely open and documented, you can decrypt files using standard command-line tools or programming languages like Python, Node.js, Go, or Rust without visiting this website.
The .enc file uses a compact, self-contained binary layout: • Bytes 0–7 (8 bytes): Magic identifier ASCII 'YLBXENC1' • Bytes 8–23 (16 bytes): Random PBKDF2 salt • Bytes 24–35 (12 bytes): Random AES-GCM IV (96-bit nonce) • Bytes 36–end: AES-256-GCM ciphertext followed by the 16-byte authentication tag. This header contains everything needed to re-derive the key and decrypt the payload when paired with your password.
Because all cryptographic transformations occur directly in your browser's RAM via the Web Cryptography API without disk streaming, file sizes are constrained by available browser memory. Files up to 500 MB encrypt and decrypt within seconds. Files larger than 1 GB can be processed on machines with ample RAM, but may cause tab memory warnings or slower performance on mobile devices.