AES Encrypt / Decrypt

🔐 AES Encrypt & Decrypt

This tool performs AES-256 symmetric encryption and decryption entirely inside your browser, with two block cipher modes available: CBC and GCM. You supply a piece of text (or a file) plus a passphrase. The tool runs that passphrase through PBKDF2 to derive the actual encryption key, encrypts the content, and prints the result as a Base64 or Hex string.

The passphrase you type is not the key itself. Key material is produced with PBKDF2-SHA256 over many hashing rounds, and you can pick how many: fast, standard, or high. More rounds means a brute-force attack costs more time, but you also wait longer for the result. GCM additionally produces an authentication tag, so decryption can detect whether the ciphertext was tampered with. CBC only encrypts; it does not verify integrity.

Nothing leaves your device. Both encryption and decryption run locally, and no text or file is uploaded to any server. Typical uses include encrypting configuration values before sending them to a colleague, keeping account credentials in a scratch file, storing sensitive notes on disk, or encrypting a file before dropping it into cloud storage.

There is no account to create, no server call, and no saved history. Every operation happens inside the page you have open, which also means nobody can help you recover a forgotten key. When you hand the ciphertext to someone else, send the key over a different channel than the ciphertext itself; keeping those two apart is what makes the encryption worth anything. If you only need to obscure text casually rather than protect it, this tool is more than enough, but treat the result as real encryption and the key as the only way back in.

✨ Features

• AES-256 symmetric encryption with a choice of CBC or GCM mode
• Keys derived through PBKDF2-SHA256 with three selectable iteration levels
• Ciphertext output available as Base64 or Hex
• Two channels: encrypt a snippet of text, or encrypt an entire file
• Built-in random key generator that produces a strong key in one click
• GCM verifies its authentication tag on decrypt, so altered data fails loudly instead of returning garbage

🚀 How to Use

1. Type the text you want to encrypt, or click the button to pick a file
2. Set the key: type one yourself, or use the generate button for a random one
3. Choose the mode (GCM is recommended), the output encoding, and the iteration count
4. Press encrypt to get the ciphertext, then use the copy button to save it
5. To decrypt, switch to the decrypt tab, paste the ciphertext, and enter the same key

⚠️ Notes

• Keep your key safe: the tool stores nothing. A lost key means the ciphertext cannot be recovered, and there is no reset path
• Both sides must match: mode, encoding, and iteration count must be identical when decrypting, or the operation fails
• GCM and CBC are not interchangeable: data encrypted with GCM cannot be decrypted with CBC, and vice versa
• Large files take longer: size is bounded by available browser memory, so compress very large files first
• Local only: closing the page discards everything in the input boxes, so copy your ciphertext out promptly