Steganography Encoder
What is Steganography Encoder
Steganography is the practice of concealing information within another medium so that the existence of the hidden message is not obvious. This tool uses the Least Significant Bit (LSB) technique: it embeds your secret text into the least-significant bits of the image — the red channel by default, or the red, green and blue channels together for up to 3× the capacity. The visual change is imperceptible to the human eye, yet the message can be recovered with the companion decoder. You can also set a password: the text is then encrypted with AES-256-GCM, so only someone with the password can read it back.
How to use
- Upload any PNG, JPG, or WebP image.
- Type your secret message in the text area.
- Check the character counter to ensure your message fits within the image capacity.
- Click Encode & Download to receive a PNG file with your message invisibly embedded.
- Share the downloaded PNG — only someone with the Steganography Decoder will be able to extract the message.
When to use it
Need to slip a note past prying eyes? Drop your message into an ordinary travel photo and post it publicly, and anyone scrolling past just sees a normal picture. Only the person you point to the decoder pulls the hidden text back out, so it works well for a private tip to a colleague or a low-key watermark on your own images.
Frequently asked questions
Will the encoded image look different?
No. The LSB technique changes only the last bit of each channel it uses — a maximum change of 1 in 255 per channel. That is invisible to the human eye, whether you hide in the red channel alone or across RGB.
Which image formats are supported?
You can upload PNG, JPG, or WebP. The output is always a lossless PNG, because JPEG compression would destroy the hidden bits.
How much text can I hide?
It depends on the image size and where you hide. A 1920×1080 image holds roughly 259 KB of text in the red channel alone, and about 3× that across the RGB channels. A password adds a small fixed overhead for the encryption header.
Can I password-protect the message?
Yes. Enter a password before encoding and the text is encrypted with AES-256-GCM (the key is stretched from your password with PBKDF2). The decoder then needs the same password; a wrong one reveals nothing. Leave it blank to hide the text in the clear.
Is my image uploaded to a server?
No. Everything runs locally in your browser using the Canvas API. Your image and message never leave your device.
Related tools
Steganography Decoder
Reveal secret text hidden inside images encoded with LSB steganography. Free, runs entirely in your browser — nothing is uploaded.
AES Text Decryption
Decrypt AES-256 encrypted text with your password in your browser. Free, private, and fully offline. No data leaves your device.
AES Text Encryption
Encrypt text with a password using AES-256 in your browser. Free, private, and fully offline. Nothing is sent to a server.