File Encryptor (AES-256)
Securely encrypt any file with a password directly in your browser. Military-grade AES-256 encryption. Your files never leave your device.
Drag & drop a file here or click to browse
Free Online File Encryptor – AES-256 Password Protection
Protect your sensitive data with our free, military-grade online file encryptor. This tool uses state-of-the-art AES-256-GCM encryption combined with PBKDF2 key derivation to lock your files securely behind a password. Since it operates entirely client-side, your files and passwords never leave your browser, ensuring 100% privacy.
How to Encrypt a File Online
- Select or drag & drop the file you want to protect into the upload area above.
- Enter a strong password. Use the built-in strength meter to ensure it is robust.
- Click 'Encrypt File'. The Web Crypto API will secure the file locally within seconds.
- Download the resulting .enc file. Store your password in a safe place!
Benefits of Client-Side AES-256 Encryption
Military-Grade Security
We use AES-256-GCM, the industry standard approved for classified information. Your password is hash-strengthened using PBKDF2 with 100,000 iterations.
Zero Uploads (100% Private)
No data is transmitted over the internet. All calculations are handled locally in your web browser. Your files are completely safe from server breaches.
Works Offline
Once loaded, the tool can run completely offline. You can disconnect your internet connection and encrypt files securely.
Open-Source Compatibility
Because we use standard cryptographic algorithms, you can decrypt your files with any standard tool or script that supports AES-256-GCM and PBKDF2.
Frequently Asked Questions (FAQ)
Is this file encryptor free to use?
Yes! This tool is 100% free, and there are no file size limits (subject to browser memory limitations) or premium tiers.
Are my files uploaded to any server?
Absolutely not. All encryption operations are conducted locally on your computer or device via the Web Crypto API. We have no backend server receiving your files.
Can I decrypt files encrypted here without this tool?
Yes. Since we employ industry-standard AES-256-GCM with PBKDF2 (100,000 iterations, SHA-256 hash), you can write a short Python or Node.js script to decrypt the files. The output format is: 1 byte salt length (32), 32 bytes salt, 1 byte IV length (12), 12 bytes IV, followed by the ciphertext.
What happens if I forget my password?
If you forget the password, the data is permanently lost. Due to the strength of AES-256, it is impossible to recover the files without the correct password. We do not store or have access to your passwords.
What algorithms are used?
The key is derived using PBKDF2 (Password-Based Key Derivation Function 2) with HMAC-SHA-256 and 100,000 iterations. The encryption uses AES-256-GCM (Galois/Counter Mode), which guarantees both confidentiality and integrity of your data.