Image Steganography (LSB)

Hide a secret message in the least-significant bits of an image, or reveal one that is already there.

Least-significant-bit (LSB) steganography hides data by nudging the lowest bit of each color channel, a change too small for the eye to see. Hide a message below and download the result as a lossless PNG, or upload a suspected stego image to reveal what is hidden inside. PNG is required: JPEG re-compression destroys the hidden bits.

Hide (Message → Image)

Cover image (PNG, BMP, or other lossless source) Secret message

Reveal (Image → Message)

Suspected stego image

Extraction mode

Auto (read the CacheSleuth header) Raw LSB dump (for images hidden elsewhere)

Revealed text

How it works

Each pixel stores red, green, and blue as numbers from 0 to 255. Changing the lowest bit shifts a value by at most 1, which is invisible. This tool walks the pixels left to right, top to bottom, and writes one bit of your message into the lowest bit of each red, green, and blue channel in turn (the transparency channel is left alone).

Hidden messages start with a short header: the marker CS followed by a 4-byte length, then the UTF-8 message bytes. The Reveal step reads that header back automatically. If an image was hidden by some other program, switch to Raw LSB dump and try different bit depths and channel orders to see what falls out.

Always export as PNG. Saving a stego image as JPEG re-compresses the pixels and wipes out the hidden bits.