Text Encryption
Encrypt and decrypt text using AES and other algorithms. Runs on your device — nothing is uploaded, nothing is stored.
Used to encrypt and decrypt. Keep it secret — you need it to decrypt later.
Enter your text, set a password above, then encrypt or decrypt.
This tool encrypts a piece of text with a passphrase and turns it back again. Type or paste your text, enter a passphrase (or press the button to generate a random 24-character key), and press Encrypt. The result is a single line of Base64 text you can paste into an email, a note or a chat. To read it later, paste that line into the same box, enter the same passphrase and press Decrypt.
Under the hood it uses AES-256 in GCM mode through the browser's Web Crypto API. The key is derived from your passphrase with PBKDF2 (SHA-256, 100,000 iterations) and a fresh random 16-byte salt, and every encryption also uses a fresh random 12-byte IV. Salt and IV are stored at the front of the output, which is why the same text and passphrase give a different result each time. GCM also authenticates the data, so a wrong passphrase or an edited ciphertext fails to decrypt instead of producing garbage.
Why this runs on your device
Your text and passphrase are processed by crypto.subtle in your own browser, and this tool has no code that sends either to a server, so we never hold anything we could read or lose. That has limits you should know about. Like any web app, it runs code the site delivers each time you load it, so it cannot protect you from a compromised device, a malicious browser extension or someone watching your screen. It also does not hide that a message exists or roughly how long it is, and the passphrase is not stored anywhere, so a forgotten passphrase cannot be recovered.
- Enter a passphrase, or press Generate random key and save it somewhere safe.
- Paste or type your text and press Encrypt.
- Copy the Base64 result and send or store it.
- To read it, paste the Base64 text back, enter the same passphrase and press Decrypt.
- Security rests on your passphrase. The 100,000-iteration PBKDF2 step slows guessing, but anyone holding the ciphertext can try passphrases offline, so a short or common one can still be cracked. Use a long passphrase or the generated random key.
- The output is this tool's own layout: Base64 of the 16-byte salt, the 12-byte IV and the encrypted data. Other programs such as OpenSSL or GPG will not open it, so you need this tool, or code that follows the same layout, to decrypt.
- It is for text, not files, and meant for notes and messages of ordinary length. Encryption does not hide the approximate length of the message.
- A wrong passphrase and a damaged or edited ciphertext give the same generic failure message, so the tool cannot tell you which it was.
- The passphrase and any generated key live only on the page. Copy a generated key somewhere safe before you leave, because reloading the page loses it.
- This is a convenience tool, not an audited secrets product. For high-stakes data use an established tool such as GPG or age.