AES Encryption Online
Encrypt text or files with AES-GCM, CBC or CTR (128, 192 or 256-bit) using a password or your own key and IV. Free, private, runs in your browser with Web Crypto.
How to use AES Encrypt
- 1Type or paste your text, or choose Encrypt file for a file up to 100 MB.
- 2Enter a password (or press Generate strong password), and pick AES-GCM and 256-bit unless you need something else.
- 3Press Encrypt, then copy the Base64 or Hex result, or download the .enc file. Keep the password: there is no recovery.
What makes it better
- AES-GCM (authenticated), AES-CBC and AES-CTR with 128, 192 or 256-bit keys
- Password mode: PBKDF2-HMAC-SHA-256 with a random salt and up to 1,000,000 iterations
- Self-describing output: decrypting needs only the password
- Key + IV mode with random key and IV generators, plus optional AAD for GCM
- Encrypts files up to 100 MB with no upload
About AES Encrypt
AES Encryption Online scrambles text or a file so that only someone with the password (or the key and IV) can read it again. By default it uses AES-256-GCM with a key stretched from your password by PBKDF2, and it packs everything needed to decrypt into one Base64 or Hex string. All the work happens in your browser with the Web Crypto API, so the text, the password and the files never leave your device.
Common uses
- Protect a note, token or snippet before pasting it into a chat, ticket or email.
- Encrypt a small file, such as a backup of exported credentials, before putting it in cloud storage.
- Produce AES test data with a known key and IV to check your own code against.
- Teach or learn how AES modes, IVs and password-based key derivation behave.
Example
Input
Meet at the north gate at 9:30. Bring the signed contract — नमस्ते 👋
Result
TlNBRQEBAwAJJ8CgoaKjpKWmp6ipqqusra6vEBESExQVFhcYGRobajFkwcbBzPjTmjRnD1Cg7oeVlpEv8uRrGMqXC1qI0TE+v4/T0ExGCiPaFohjXRr3sdwjYWlpYtbfMNBa76Z5XksthtOMVeE4uXGIZaK9qsobwrq6sR7flbxRweURcAPc8tEQu+4=
Good to know
- Example: encrypting the sample text with the password example-password. Every real encryption uses a fresh random salt and IV, so your output will differ even for the same text and password.
- If you lose the password the data cannot be recovered by anyone, including us. Nothing is stored or sent anywhere.
- PBKDF2 is slower to attack than a plain hash, but weaker than Argon2 or scrypt, which browsers do not provide. Use a long, random password. For production systems use a reviewed library and a password manager, not a web page.
AES Encrypt FAQ
Is AES-256 secure?
AES itself has no practical attack, and 256-bit keys are used by governments and banks. In practice the weak point is the password: someone who guesses it can decrypt everything. Choose a long random password and prefer GCM, which also detects tampering.
Why do I get a different result every time I encrypt the same text?
Each encryption picks a new random salt and IV (initialisation vector). That is deliberate: it stops anyone from telling that two messages are identical and keeps the key unique per message. All of them still decrypt with the same password.
What is the difference between AES-GCM, CBC and CTR?
GCM encrypts and adds an authentication tag, so wrong passwords or edited data are detected. CBC and CTR only hide the content; if someone changes the ciphertext you may get garbage without an error. Choose GCM unless you must match an existing system.
Can I use this for data that other software must decrypt?
In Password mode the output follows this tool's own envelope format (documented under Format details), so other software has to parse it first. For interoperability with OpenSSL, Node or Python, switch to Key + IV mode, which outputs plain AES ciphertext.
Why are DES, 3DES, RC4, Blowfish and ECB missing?
They are obsolete or unsafe. DES and RC4 are broken, 3DES and Blowfish have small 64-bit blocks, and ECB mode shows patterns in your data. AES with GCM, CBC or CTR is what current guidance recommends, so that is all this page offers.