Encrypt Text Online

The Text Encrypter is a browser-based utility that takes any plain readable message and scrambles it into an unreadable encrypted string (ciphertext) using AES-256 encryption. The result can only be reversed by someone who has the correct password and uses the matching Decrypt tab. All processing happens locally in your browser via the Web Crypto API — your text and password are never sent anywhere.

Encrypting text protects sensitive information from being read by anyone who shouldn’t have access to it. Common reasons include securing passwords, private notes, or credentials before storing them somewhere, safely sharing a confidential message with someone by sending the encrypted output and the password separately, protecting personal data at rest in case a file or device is compromised, or simply ensuring that even if someone intercepts your text, it is completely unreadable without the key.

There are several interactive controls in the Encrypt panel. The Clear button (top right of the text area) wipes your input message so you can start fresh. The eye toggle beside the password field reveals or hides your password as you type. The preset algorithm buttons (AES-256-GCM and AES-256-CBC) let you choose which encryption mode to use. The Base64 and Hex toggles control the format of the encrypted output — Base64 produces a shorter string while Hex produces a longer human-readable hexadecimal one. The Encrypt button runs the full encryption process and displays the result. The Copy button in the output area copies the encrypted string to your clipboard instantly.

Like the Decrypt tab, this tool is designed for text content pasted into the textarea — messages, notes, credentials, and similar strings. There is no enforced character limit in the code, but very large inputs will consume more browser memory since everything is processed in-place on the client side. It is not intended for binary files or documents. For best performance and usability, it is most suited to text that would reasonably fit in a text field.

When you click Encrypt, the tool first generates two random values using crypto.getRandomValues() — a 16-byte salt and either a 12-byte IV (for AES-GCM) or a 16-byte IV (for AES-CBC). It then takes your password and runs it through PBKDF2 with the salt and 100,000 iterations of SHA-256 to derive a strong 256-bit AES key. This key derivation step means your password is never used directly — instead a hardened key is computed from it, making brute-force attacks significantly slower. The tool then encrypts your message using crypto.subtle.encrypt() with the chosen algorithm and IV. Finally, it packs everything needed for future decryption — an algorithm flag byte, the salt, the IV, and the ciphertext — into a single byte array and encodes it as Base64 or Hex depending on your toggle selection. That final string is what gets displayed in the output and is the only thing you need to share or store.

Completely. It’s a single HTML file that runs entirely in your browser with no account, no backend, no telemetry, and no cost. You can save it to your desktop and use it offline indefinitely.