Hide a message inside ordinary-looking text.

The visible text and the hidden message are separate. plaintext.fun can choose an English cover sentence automatically, or you can write the visible text yourself. The hidden data is inserted afterwards.

message → optional encryption → invisible Unicode → visible text

Enter the message you want to hide. Leave the visible text on Automatic to use a local English sentence, or choose My own text and write exactly what people should see. Then select Hide message and copy the result unchanged.

Automatic mode uses a small built-in bank of curated English sentences in different lengths. A sentence is selected locally in your browser, so there is no AI model to download and no generation request to wait for.

Paste the complete visible text without editing it, then select Reveal. plaintext.fun reads the invisible characters and reconstructs the original hidden message.

A password is optional. If you add one, plaintext.fun derives an encryption key with PBKDF2 and encrypts your message with AES-256-GCM before hiding it.

Without a password, the message is hidden but not encrypted. Someone who has the visible text and knows how this encoding works can reveal it.

Your message and password are processed in your browser. Automatic cover text is selected from the local sentence bank, and your hidden message is inserted only afterwards.

There is no model inference or application backend involved in creating the cover text.

• Keep the final visible text unchanged. Editing, retyping, translating or reformatting it can damage the hidden data.
• Some apps and services may remove or normalize invisible Unicode characters. If that happens, the hidden message may not survive.
• If you use a password, the recipient needs the same password to reveal the message.
• If confidentiality matters, use a password. Hiding a message is not the same as encrypting it.