AES Encrypt & Decrypt Tool
Free online AES encrypt/decrypt tool. Securely encrypt or decrypt text with AES-128, AES-192, or AES-256 in GCM mode using a password. PBKDF2 key derivation.
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What is AES Encrypt & Decrypt Tool?
The AES Encrypt & Decrypt tool uses the Web Crypto API to perform authenticated AES-GCM encryption directly in your browser. You supply a password; the tool derives a strong AES key from it using PBKDF2 (150,000 iterations, SHA-256) with a fresh random salt every time, then encrypts your text with AES-128, AES-192, or AES-256. The output is a single base64 string that bundles the salt, IV, ciphertext, and authentication tag — portable and safe to paste anywhere. Nothing ever leaves your device.
Key Benefits
- Industry-standard AES-GCM authenticated encryption (NIST-approved)
- Password-based key derivation via PBKDF2 protects against brute-force attacks
- Fresh random salt and IV for every encryption — identical plaintexts never produce the same ciphertext
- AES-128, AES-192, and AES-256 selectable to match your security requirements
- 100% client-side via the Web Crypto API — no network calls, no server storage
Common Use Cases
- •Encrypting sensitive notes or secrets before pasting them into chat or email
- •Developers testing AES-GCM round-trips against their own backends
- •Sharing credentials or tokens through insecure channels with a shared password
- •Students learning how symmetric authenticated encryption works in practice
- •Anyone who needs trustworthy encryption without installing software
How to Use the AES Encrypt & Decrypt Tool
- Pick a Mode: Choose Encrypt to turn text into a base64 ciphertext, or Decrypt to convert a base64 ciphertext back into readable text. Both operations use the same password.
- Choose a Key Length: Select AES-128, AES-192, or AES-256. AES-256 provides the strongest security and is recommended for sensitive data. Both sides must use the same key length.
- Enter Your Password: Type a strong password. The tool derives an AES key from it using PBKDF2 with 150,000 iterations and a random salt, so even a modest password resists brute-force attacks.
- Encrypt or Decrypt: Click the button to run the operation. Copy the result or use Swap to move it into the other mode for a quick round-trip verification.
Key Features
- AES-GCM authenticated encryption (AES-128, AES-192, or AES-256)
- Password-based key derivation via PBKDF2 (150,000 iterations, SHA-256)
- Random salt and IV generated for every encryption — never reused
- Base64 output bundles salt, IV, and ciphertext into one portable string
- Swap button flips encrypted output back into decrypt input instantly
- Runs entirely in your browser via the Web Crypto API — no network calls
Frequently Asked Questions
Is AES-GCM secure for encrypting sensitive data?
Yes. AES-GCM is an authenticated encryption mode approved by NIST and used across TLS, VPNs, and disk encryption. The tool uses AES-256 by default with PBKDF2 key derivation (150,000 iterations). Security depends on the strength of your password — use a long, random passphrase for best results.
What is inside the base64 output?
The output bundles three things: a 16-byte random salt, a 12-byte random IV (nonce), and the AES-GCM ciphertext with its authentication tag. All three are needed to decrypt, so copy the entire string — truncating it will cause decryption to fail.
Why does decrypting fail with an error?
The most common cause is a wrong password. Because AES-GCM is authenticated, an incorrect password or a tampered ciphertext is detected and decryption fails rather than producing garbage. Also check that the key length (128/192/256) matches what was used to encrypt, and that the base64 string was copied in full.
Can I decrypt ciphertext encrypted by another AES tool?
Only if that tool uses the same format: PBKDF2-SHA256 with 150,000 iterations, AES-GCM, a 16-byte salt prepended to a 12-byte IV, and base64 encoding. Standard AES-CBC or raw AES-GCM outputs from other tools use different formats and will not decrypt here without matching all parameters.