Text Encryptor
Encrypt and decrypt text using AES-256-GCM encryption
How to use this tool
- Enter the text you want to encrypt or decrypt
- Enter a strong password (remember this password!)
- Click Encrypt or Decrypt based on your needs
- Copy the result using the copy button
About this tool
Encrypt a piece of text with a password, and decrypt it again with the same password, without any of it leaving your device. The algorithm is AES-256 in GCM mode. AES-256 is the block cipher used to protect classified government material and is not known to be broken by any practical attack. GCM is an authenticated mode, which adds something a plain cipher does not have: it detects tampering. If a single character of the ciphertext is altered in transit, decryption fails outright rather than quietly producing wrong plaintext, so you learn that the message was damaged instead of trusting a corrupted result. The password is the whole of the security. It is never stored, never transmitted and never recoverable, which is exactly what makes the encryption meaningful and exactly what makes it unforgiving: forget the password and the text is gone permanently. There is no reset and no back door, by design. The practical part people get wrong is delivery. Sending the encrypted block and the password in the same email defeats the entire exercise, because anyone who reads that email has both halves. Send the ciphertext one way and the password another: message it, say it on a call, hand it over in person. This is a tool for a specific job, not a security system. It is well suited to sending a short secret through an untrusted channel, or to storing a note somewhere you would rather it was not readable. For continuous protection of many secrets, use a dedicated password manager or full disk encryption instead.
Frequently asked questions
What encryption does this use?
AES-256 in GCM mode, with the key derived from your password. AES-256 is the standard used for classified government data, and GCM is an authenticated mode, meaning it detects tampering as well as hiding content: altered ciphertext fails to decrypt rather than silently producing wrong plaintext.
What happens if I forget the password?
The text is unrecoverable. There is no reset, no recovery code and no back door, because the password is never stored anywhere and nothing about it leaves your browser. That is the property that makes the encryption meaningful, and it is unforgiving. Save the password before you close the tab.
How do I share encrypted text safely?
Send the ciphertext and the password through different channels. Emailing both together defeats the point entirely, since anyone reading the email has everything. Send the encrypted block by email and the password by phone, or by a separate messaging app.
Is my text sent to a server?
No. Encryption and decryption both run in your browser using the Web Crypto API. Neither the plaintext, the ciphertext nor the password is ever transmitted, stored or logged.
Why does decryption fail even with the right password?
Almost always because the ciphertext was altered in transit. A missing character, an added line break, or a mail client wrapping the text will all break it, because GCM verifies integrity before it decrypts. Copy the encrypted block whole and paste it without editing.
Is this suitable for protecting really sensitive information?
The algorithm is, but a single tool is not a security system. Strength depends on the password you choose, on the device you type it on being clean, and on how carefully you handle the ciphertext. For sustained protection of high-value secrets, use audited software such as a password manager or full disk encryption.