Hide text in a photo
Tuck a message into a picture's pixels
Least-significant-bit steganography writes your text into the lowest bit of each colour value, where it changes the picture too little to see. Hide a short note in a photo, or drop in a photo to reveal a message someone hid this way. It stays a picture you can open anywhere.
Runs entirely in your browser. Your file is never uploaded or stored.
How hiding text in a picture works
Every pixel is three colour values, red, green and blue, each a number from 0 to 255. The lowest bit of that number barely shifts the colour, by one step out of 256, so changing it is invisible. This tool walks the pixels and writes your message one bit at a time into those lowest bits. The picture looks identical; the note rides along inside it. To read it back, the reveal tab walks the same pixels and reassembles the bits into text.
Save as PNG, not JPEG
The hidden message lives in the exact pixel values, so it only survives a lossless format. This tool always saves a PNG for that reason. If you re-save the result as a JPEG, or let a chat app or social network re-compress it, the low bits are rewritten and the message is gone. Share the PNG as a file, an attachment or a download, not through anything that re-encodes images.
This is hiding, not encryption
Steganography conceals that a message exists; it does not protect the message. Anyone who suspects a photo carries LSB data can pull it out with a tool like this one, and simple statistical tests can flag that something is hidden. If the contents matter, encrypt the text first and hide the result, so that even if it is found it cannot be read.