How to Encrypt Text With AES (Without Trusting a Website)
A few years ago I needed to send a server password to a colleague over chat. I pasted it into the first 'free AES encryptor' Google showed me, copied the output, and sent it along. It worked — and then it hit me: I had just handed my plaintext password to a stranger's server and hoped they were honest. That's not encryption. That's a pinky promise.
This guide fixes that mistake. I'll explain how AES-256 actually protects your text, why your password matters more than the algorithm name, and how to encrypt and decrypt messages so that no server, no company, and no eavesdropper ever sees the readable version.
What AES-256 is and why everyone uses it
AES (Advanced Encryption Standard) is a symmetric cipher: the same password that locks your text unlocks it. The '256' is the key length in bits. To put that in perspective, trying every possible 256-bit key would take longer than the age of the universe, even with every computer on Earth working together. That's why banks, governments, and messaging apps all rely on it.
The important detail most guides skip: AES itself is rarely the weak point. When encrypted messages get exposed, it's almost always because of a weak password, a sloppy implementation, or the plaintext being sent to a server first. The algorithm is the strongest link in the chain — which means your job is to not weaken everything around it.
Your password matters more than the algorithm
AES-256 with the password 'password123' is theater. Attackers don't break the math; they guess the password. A good encryption password is long and unique — ideally a random passphrase of five or more words, or a 20+ character random string from a password generator.
- Use a unique password you don't reuse anywhere else.
- Longer beats complex: a 25-character passphrase outlives an 8-character symbol soup.
- Store the password in a password manager, not in the same chat thread as the encrypted text.
If you take one thing from this article, take this: the encryption is only as strong as the secret you choose. I generate mine fresh for every sensitive message and never reuse them — and if I'm not sure one is up to the job, I run it through our Password Strength Checker first to see its estimated crack time. (I wrote a full guide on creating a strong password you'll actually remember if you want the deeper version.)
How our AES tool protects you (the honest version)
When you encrypt text with our free AES Text Encryptor, everything happens inside your browser tab using the Web Crypto API — the same audited cryptography built into Chrome, Firefox, Safari, and Edge. Your password goes through PBKDF2 key derivation (250,000 iterations) to produce the actual 256-bit key, and the text is sealed with AES-GCM, which also detects tampering.
- Type or paste your text and choose a strong password.
- Click Encrypt. The tool derives a key, generates a random salt and IV, and outputs base64 text.
- Send the base64 blob through any channel. Only someone with the password can decrypt it.
Nothing is uploaded. There is no server to get hacked, no database of your messages, no 'we promise we don't log' policy to trust. Close the tab and the plaintext is gone from memory.
When AES alone isn't enough
I'll be straight with you: encryption doesn't solve every problem. If the recipient's device is compromised, if you send the password through the same channel as the ciphertext, or if someone is looking over your shoulder, AES can't help. For truly sensitive material, share the password through a different channel than the encrypted text — say the ciphertext by email and the password by a phone call.
Also remember that encryption hides content, not metadata. An observer can still see that you sent a message, when, and to whom — just not what it says. That's usually fine for passwords, notes, and private messages, which is what this tool is built for.