AES-256 Decrypt Online
Decrypt AES-256-GCM or CBC ciphertext using a password. Nothing ever leaves your browser.
Paste ciphertext and enter the password to decrypt
This tool runs entirely in your browser. Your password and data never leave your device.
AES Decryption FAQ
Why does decryption fail?
The most common reasons are: (1) wrong password, (2) wrong algorithm — make sure GCM/CBC matches what was used for encryption, (3) the ciphertext was modified or truncated, or (4) the input is not valid Base64.
Can I decrypt data encrypted elsewhere?
Yes, as long as the data uses the same wire format: Base64-encoded salt (16 bytes) + IV (12 bytes for GCM, 16 for CBC) + ciphertext, with the key derived via PBKDF2 (100k iterations, SHA-256).
What is authenticated decryption?
AES-GCM produces an authentication tag alongside the ciphertext. During decryption, this tag is verified to ensure the data was not tampered with. If verification fails, decryption is rejected entirely — this is a security feature.
Is my data safe?
Absolutely. All processing happens in your browser using the Web Crypto API. Your password, plaintext, and ciphertext never leave your device. No data is sent to any server.
Need to share encrypted data securely?
Don't paste credentials into chat or email. Use CredenShare to deliver them with AES-256 encryption and automatic expiration.