AES Encryption Tool
Secure AES encryption and decryption with multiple modes
Encryption Settings
Encrypt
Decrypt
AES Encryption Online — Secure Your Data Instantly
Encrypt and decrypt text or files using the Advanced Encryption Standard (AES) directly in your browser. Our free client-side AES encryption tool ensures your sensitive data never leaves your device.
What is AES Encryption?
AES (Advanced Encryption Standard) is a symmetric-key block cipher adopted by the U.S. National Institute of Standards and Technology (NIST) in 2001. It encrypts data in fixed 128-bit blocks using key sizes of 128, 192, or 256 bits. AES replaced the older DES standard and is now the most widely used encryption algorithm in the world.
Trusted by governments, banks, military organizations, and enterprises worldwide, AES provides the gold standard in symmetric encryption. Its combination of speed, security, and efficiency makes it ideal for protecting everything from classified documents to everyday web traffic via HTTPS.
Key Features
AES-128/192/256 Support
Choose the key size that fits your security requirements. All three standard AES key lengths are supported, from fast 128-bit encryption to maximum-strength 256-bit.
Multiple Modes (CBC, ECB, CFB, OFB)
Select from industry-standard block cipher modes of operation. Each mode offers different trade-offs between security, error propagation, and performance.
Client-Side Processing
All encryption and decryption happens entirely in your browser. Your plaintext, keys, and ciphertext are never transmitted to any server, ensuring total privacy.
Random Key Generation
Generate cryptographically secure random keys with a single click. Uses the Web Crypto API to produce truly random keys suitable for production use.
Real-Time Encrypt/Decrypt
Instantly encrypt or decrypt your data with immediate results. No waiting for server responses — everything processes locally with minimal latency.
File Encryption Support
Encrypt and decrypt files directly in the browser. Upload any file type and download the encrypted or decrypted result securely without size limitations.
How to Encrypt Text with AES
Enter Your Text or Upload a File
Paste the plaintext you want to encrypt into the input area, or upload a file directly. The tool accepts any text content or file format for encryption.
Choose Encryption Mode and Key Size
Select your preferred AES mode (CBC, ECB, CFB, or OFB) and key size (128, 192, or 256 bits). Enter your own secret key or generate a random one automatically.
Click Encrypt and Copy or Download the Result
Hit the encrypt button to generate the ciphertext instantly. Copy the encrypted output to your clipboard or download it as a file for secure storage and sharing.
AES Encryption Modes Explained
CBC (Cipher Block Chaining)
The most widely recommended mode. CBC uses an initialization vector (IV) and chains each block to the previous one, meaning identical plaintext blocks produce different ciphertext. Best choice for general-purpose encryption.
ECB (Electronic Codebook)
The simplest mode but the least secure. Each block is encrypted independently, so identical plaintext blocks produce identical ciphertext blocks. Not recommended for encrypting data larger than a single block.
CFB (Cipher Feedback)
Operates as a stream cipher mode, allowing encryption of smaller units of data than the full block size. Useful for encrypting data streams where block alignment is not guaranteed.
OFB (Output Feedback)
Another stream cipher mode where the output of the encryption function feeds back into the next iteration. A key advantage is that bit errors in the ciphertext do not propagate to the decrypted plaintext.
When to Use AES Encryption
- API Key Protection: Encrypt API keys and tokens before storing them in configuration files or environment variables.
- Sensitive Data Sharing: Securely share confidential information with colleagues or clients by encrypting the data before transmission.
- File Encryption: Protect sensitive documents, spreadsheets, and other files with strong AES encryption before uploading to cloud storage.
- Password Storage: Encrypt password databases and credential files to add an extra layer of security beyond hashing.
- Secure Communications: Encrypt messages and data payloads for secure communication channels between applications or users.
Frequently Asked Questions
Is AES-256 more secure than AES-128?
Both AES-128 and AES-256 are considered secure against brute force attacks with current technology. AES-256 provides a larger key space (2^256 vs 2^128), making it theoretically more resistant to future quantum computing threats. For most use cases, AES-128 offers excellent security with slightly better performance.
What encryption mode should I use?
CBC (Cipher Block Chaining) is the most recommended mode for general-purpose encryption. It provides strong security by chaining blocks together and using an IV. Avoid ECB for anything beyond single-block encryption, as it reveals patterns in your data.
Is my data safe with this tool?
Yes. All encryption and decryption operations run entirely in your browser using JavaScript. Your plaintext, encryption keys, and ciphertext are never sent to any server. You can verify this by monitoring network traffic in your browser's developer tools.
Can I decrypt without the original key?
No. AES is a symmetric encryption algorithm, which means the same key used for encryption must be used for decryption. If you lose the key, the encrypted data cannot be recovered. Always store your encryption keys securely and create backups.
What is the difference between AES and RSA?
AES is a symmetric encryption algorithm, using the same key for both encryption and decryption. RSA is an asymmetric algorithm that uses a public key for encryption and a private key for decryption. AES is much faster and used for bulk data encryption, while RSA is typically used for key exchange and digital signatures.
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