Free AES Encryption & Decryption Online

Protect your sensitive data with our free AES encryption tool. It uses the industry-standard AES algorithm to securely encrypt text or files directly in your browser. No data is uploaded, ensuring complete privacy.

Mode

Key Size

Encryption Key (Hex)

0/64

Text to Encrypt

About AES Encryption

AES (Advanced Encryption Standard) is a symmetric encryption algorithm widely used for securing sensitive data. This tool uses AES-GCM mode which provides both confidentiality and authenticity. The key must be kept secret - anyone with the key can decrypt the data. Store your key securely!

How It Works

This AES encryption tool uses the Advanced Encryption Standard with Galois/Counter Mode (GCM) to securely encrypt and decrypt your data directly in your browser.

The encryption process:

Key generation: Create a random hex key of 128, 192, or 256 bits, or enter your own.
IV creation: A unique initialization vector (12 bytes) is generated for each encryption.
AES-GCM encryption: Your data is encrypted using AES in GCM mode, which provides both confidentiality and authenticity.
Output formatting: The IV and encrypted data are combined and output as a hex string.

Decryption reverses this process: the IV is extracted from the encrypted data, then AES-GCM decrypts using your key. If the key is wrong or data is corrupted, decryption fails - ensuring data integrity.

When You'd Actually Use This

Secure Password Storage

Encrypt sensitive passwords before storing them in databases or configuration files.

Private Message Exchange

Encrypt messages that you'll share through insecure channels - only recipients with the key can read them.

Configuration File Protection

Encrypt API keys, tokens, and secrets in config files that might be exposed in version control.

Backup Encryption

Encrypt sensitive data before backing it up to cloud storage or external drives.

Secure Data Transmission

Pre-encrypt data before sending it over networks where additional security layers might be needed.

Learning Cryptography

Understand how symmetric encryption works by experimenting with different keys and observing the output.

What to Know Before Using

Key security is everything

AES is symmetric - the same key encrypts and decrypts. Anyone with the key can read your data. Store keys separately from encrypted data.

256-bit is the strongest option

While 128-bit AES is still considered secure, 256-bit provides maximum protection against future advances in computing power.

Each encryption produces different output

Even with the same key and text, encryption generates a random IV each time. This is normal and actually improves security.

Encrypted data is larger than original

The output includes the 12-byte IV plus authentication tags, making it about 24-32 bytes larger than the original text.

Lost key means lost data forever

There's no backdoor or recovery. If you lose the encryption key, your data is permanently inaccessible. Back up your keys!

Common Questions

Is AES-256 really unbreakable?

AES-256 has never been cracked through brute force. With 2^256 possible keys, even the world's fastest supercomputers would take billions of years to try all combinations.

What's the difference between AES-GCM and AES-CBC?

GCM (Galois/Counter Mode) provides both encryption and authentication - it detects tampering. CBC only encrypts. GCM is faster and more secure for most use cases.

Can I use the same key for multiple encryptions?

Yes, but each encryption uses a different random IV. Never reuse the same IV with the same key - that compromises security. This tool handles IV generation automatically.

Why is the encrypted output in hexadecimal?

Encrypted data is binary (raw bytes). Hex encoding makes it safe to copy, paste, and store as text. Each pair of hex characters represents one byte.

Is my data sent to a server?

No. All encryption happens in your browser using the Web Crypto API. Your data and keys never leave your device.

How long should my key be?

For 128-bit: 32 hex characters. For 192-bit: 48 hex characters. For 256-bit: 64 hex characters. Use the Generate button for cryptographically secure random keys.

Can I encrypt files with this tool?

This tool encrypts text. For files, you'd need to convert them to base64 first, then encrypt the resulting string. Consider dedicated file encryption tools for large files.

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