Image LSB Steganography
Hide a secret message inside an image by writing it into the least-significant bits of its pixels — the cover looks unchanged — then reveal it again. Optionally key the bits with a password so only someone who has it can extract the message. Everything runs locally in your browser; nothing is uploaded.
or drop / paste (Ctrl/⌘+V). PNG works best — the output is lossless PNG.
How it works: the message is UTF-8 encoded, a 4-byte length header is prepended, and the resulting bits are written into the lowest bits of each selected color channel, walking pixels left-to-right, top-to-bottom. If a password is given, each stored bit is XOR-ed with a keystream seeded from it (mulberry32 + FNV-1a), so extraction needs the same password. This is steganography, not encryption — it hides the message's existence, not its meaning; a determined analyst can still find the bits. Important: always keep the output as PNG — JPEG/WebP re-encoding destroys the least-significant bits and the message becomes unrecoverable. No network requests are made.