Encrypt any text with AES and a secret key, right in your browser. Nothing is uploaded.
AES Encryption lets you scramble a message, note, API token, or config value into unreadable ciphertext using the Advanced Encryption Standard — the same symmetric cipher trusted by banks, VPNs, password managers, and governments to protect data at rest and in transit. You supply the text and a secret key; the tool returns a compact block of ciphertext that is useless to anyone who does not know your key. Because everything happens inside your browser tab, your plaintext and your key are never transmitted, stored, or logged anywhere.
AES (the Advanced Encryption Standard) is a symmetric block cipher adopted by the U.S. National Institute of Standards and Technology in 2001 and used worldwide ever since. Symmetric means a single shared key both encrypts and decrypts the data, which makes AES fast and ideal for protecting content when both sides can share a secret in advance. It operates on fixed-size blocks of data and supports key sizes of 128, 192, and 256 bits, with larger keys offering a wider margin of safety.
When you type a passphrase, the tool derives an encryption key from it and transforms your text block by block, mixing and substituting bytes through multiple rounds until the output bears no visible relationship to the input. Each round applies substitution, permutation, and key-mixing steps that thoroughly scramble the data. The result is typically shown as a Base64 string so it can be safely copied and pasted into chats, tickets, emails, or documents without corruption. To read it again, you or your recipient run the AES Decryption tool with the exact same key.
Say you want to send a meeting location privately:
Meet me at the cafe at 5pmblue-otter-42U2FsdGVkX1+9Yb3kQ2m8Zr7xnP0aVt6...You send only the ciphertext over a public channel. Even if someone intercepts it, they see gibberish. Your recipient pastes it into the decryptor, enters blue-otter-42, and instantly reads the original sentence. Change a single character of the key and decryption fails — that is the whole point.
The cipher is only as strong as the key and how you handle it. Choose a long, unpredictable passphrase — a short word like cat can be guessed quickly, whereas something like correct-horse-battery-staple-91 is far harder to attack. Never send the key through the same channel as the ciphertext; if a snooper sees both together, the protection is gone. Share the key in person, through a separate app, or via a password manager. Finally, remember that encryption protects confidentiality, not integrity or authenticity on its own, so pair it with trusted delivery for sensitive workflows.
Uploading sensitive text to a remote encryption service defeats the purpose — you would be handing your plaintext to a third party. This tool computes everything locally in JavaScript, so there is no server round-trip, no logging, and no account. When you close the tab, nothing is retained.
AES is one of the most rigorously analysed and widely trusted ciphers in the world. Its real-world strength depends on your key: use a long, unpredictable passphrase and share it only through a separate, trusted channel.
No. Both the encryption and the key handling happen entirely in your browser. Nothing is sent to a server.
Open the AES Decryption tool, paste the ciphertext, and enter the identical secret key you used to encrypt.
Length and unpredictability. A short word is weak; a long passphrase of several unrelated words is far harder to guess or brute-force.
Encoding (like Base64 or hex) simply changes how data is represented and can be reversed by anyone. Encryption requires a secret key, so only someone with the key can read the result.
Yes — you can encrypt anything from a single word to long multi-paragraph messages.
No. Hashing is one-way and cannot be reversed; AES encryption is two-way and is designed to be decrypted with the correct key.
Pair this with the AES Decryption tool to reverse the process, or explore other encoding utilities like the Data URI Generator and ASCII to Hex Converter.
How to Use AES Encryption — Encrypt Text Online
Type or paste the message you want to encrypt into the input box.
Choose a long, unpredictable passphrase and share it only through a trusted channel.
Copy the encrypted output and send it. Decrypt later with the exact same key.
Encrypt any text with AES and a secret key, right in your browser. Nothing is uploaded.
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Sep 11, 2026Type:
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