AES Encryption Tool
Encrypt text with a passphrase using AES-256 GCM or CBC.
🔒AES Encryption Tool
All processing happens locallyWhat this tool does
AES Encryption Tool is an AES symmetric cipher built on the browser WebCrypto API, implements the standard table both ways and locates invalid bytes instead of silently dropping them.
The key is stretched from your passphrase with 120k PBKDF2 iterations, and a random salt plus IV are packed into the ciphertext, so encrypting the same text twice yields different output — that is expected. GCM authenticates the data and detects tampering, while CBC does not. There is no passphrase recovery.
How to use it
- Paste or type your content into the input field at the top, or press the sample button to load demo data.
- Adjust the options below the input, such as output format, separators, letter case or precision.
- Press the main button to run the conversion. Results appear instantly in the output panel without a page reload.
- When the result looks right, use the copy button in the corner, or download it as a local file.
Tips and notes
Clean up stray spaces and line breaks before pasting for more accurate results.
FAQ
A fresh random salt and IV are generated on every run and packed with the ciphertext. That is normal and they are read back automatically at decryption.
No. Nothing is stored; the key exists only in memory for that single operation.
Prefer GCM, which provides confidentiality plus integrity so tampering fails loudly. CBC alone needs a separate MAC to be safe.
WebCrypto is only available in a secure context (HTTPS or localhost) — a browser restriction that stops injected scripts from stealing keys.
The bytes are invalid in the chosen encoding — usually the wrong codec.
Yes. The tool is completely free with no usage limits, and you never need an account or a sign-in.
No. All processing runs locally in your browser, so the input never reaches a server and is never logged or stored.
Yes. The layout is mobile-first, so inputs and buttons stay comfortable on phones and tablets in both orientations.
Yes. A copy button in the output panel puts the result on your clipboard, and you can also download it as a text file.