Encrypt and decrypt text using military-grade AES-256-GCM encryption. All processing happens in your browser. Free online encryption tool.
What Is AES-256 Text Encryption & Decryption Online?
Text encryption transforms readable text (plaintext) into an unreadable scrambled format (ciphertext) using an algorithm and a secret key. Only someone with the correct key can decrypt the ciphertext back into the original message. This is the fundamental mechanism that protects sensitive data in messaging apps, banking, email and online transactions.
This tool provides client-side encryption using established algorithms. Your text and key never leave your browser — the encryption and decryption happen entirely on your device. This makes it suitable for encrypting sensitive notes, messages or data before sharing through less secure channels.
How to Use This Tool
Enter the text you want to encrypt in the input field.
Choose an encryption method from the available algorithms.
Enter a secret key (password) that will be needed to decrypt.
Click "Encrypt" to generate the ciphertext.
Share the ciphertext through any channel — only someone with the key can read it.
To decrypt, paste the ciphertext, enter the same key and click "Decrypt".
Tips & Best Practices
Use a strong, unique key for encryption — the security of the encrypted text depends entirely on the key strength.
Share the key through a different channel than the encrypted message (e.g. message via email, key via phone).
All encryption happens in your browser — your text and key are never sent to a server.
If you lose the encryption key, the data cannot be recovered — there is no "forgot password" for encryption.
Common Use Cases
Sending sensitive information through channels that may not be fully secure.
Encrypting personal notes or journal entries for privacy.
Sharing confidential data with colleagues who have the decryption key.
Learning how encryption works through hands-on experimentation.
Frequently Asked Questions
How secure is AES-256 encryption?
AES-256 is used by governments and militaries worldwide. It would take billions of years for modern computers to brute-force a 256-bit key. Combined with GCM mode, it provides both confidentiality and authenticity.
Is my encrypted data sent to a server?
No. All encryption and decryption happens locally in your browser using the Web Crypto API. Your text and password never leave your device.