AES-256 encryption
Encrypt text with a password using AES-256-GCM, then decrypt it. Key derived with PBKDF2, everything happens in your browser: nothing is sent.
- Free
- No sign-up
- No file uploaded
- Windows, Mac, Android, iPhone
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About this tool
Protect a text with a password: it is encrypted with AES-256-GCM, the algorithm used by banks and messaging apps, and turned into an unreadable Base64 block you can send or store. Only someone who knows the password can decrypt it here. Everything happens in your browser.
When to use it
Sending sensitive information
An access code, a Wi-Fi key or credentials to share: encrypt them, send the ciphertext by email and give the password through another channel (phone, text message).
Keeping a private note
Store confidential information in a file, ticket or shared document in encrypted form: it stays unreadable for anyone without the password.
Testing encryption
Developers and students can watch AES-GCM at work: the same text gives a different result every time thanks to the random salt and initialisation vector.
How to use
- Type the text and a password.
- Click Encrypt and copy the result.
- To read it, paste it in Decrypt mode with the same password.
How it works
The password is not used directly as the key: it goes through PBKDF2 with SHA-256, 310,000 iterations and a random salt, producing a 256-bit key and making brute-force attacks very costly. The text is then encrypted with AES-GCM and a random 12-byte initialisation vector.
The output bundles the salt, initialisation vector, ciphertext and authentication tag, Base64-encoded. GCM mode authenticates the message: if a single character is changed, or the password is wrong, decryption fails instead of producing wrong text. Everything is computed by Web Crypto, built into the browser.
Tips for best results
- Choose a long passphrase (four words or more): security depends above all on the password.
- Never send the password through the same channel as the ciphertext.
- A forgotten password cannot be recovered: store it in a password manager.
- To encrypt files or exchange regularly, prefer dedicated tools such as age, GPG or an end-to-end encrypted messenger.
- The ciphertext can be pasted anywhere (email, note, ticket): it contains only Base64 characters.
Common problems and fixes
“Wrong password or modified message”
Check the password (case, spaces) and that the ciphertext was copied in full, with no character added or removed.
I can't decrypt text from another tool
Each tool has its own format (key derivation, order of parts). This tool only decrypts texts it encrypted.
Encryption takes a second
That's intended: PBKDF2's 310,000 iterations also slow down attacks that try millions of passwords.
Frequently asked questions
Are my text or password sent anywhere?
No. Encryption and decryption are done by Web Crypto in your browser; nothing is transmitted or stored.
Is AES-256 secure?
Yes, it is the symmetric encryption standard used by governments and banks. The possible weakness is the chosen password, not the algorithm.
Why does the result change every time?
A random salt and initialisation vector are drawn for each encryption, so two ciphertexts never reveal that they hide the same message.
Can you recover a text if I lost the password?
No, nobody can: that is the guarantee of real encryption.
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Still stuck?
Ask on the forum: the category, the tool, your device sheet and the test result will be filled in for you.