LSB steganography extract
Pull the least-significant bit out of an image's colour channels and check whether it spells out readable text. Finding nothing proves nothing; finding text does not prove it was hidden on purpose.
Runs on your device. The file is never uploaded.
LSB steganography extract reads the low bit of each selected colour channel, packs the bits eight to a byte and reports runs of 8 or more printable characters. A PNG of that bit-plane, ending -lsb-plane.png, comes back too. An empty report rules out that one layout and nothing else; a different bit or channel order reads as noise.
Questions
What exactly does it extract?
The least significant bit of each selected colour channel, read in pixel order and then channel order, packed eight bits to a byte with the first bit as the most significant. That is the layout the classic hide-text-in-the-LSBs tools use. The resulting bytes are filtered to printable ASCII, split on anything else, trimmed, and any run of 8 or more characters is reported, up to the first 50 runs.
I got nothing back. Is the image clean?
No, and the tool says so in the result: no run of 8 or more printable ASCII characters was found in that stream, which does not rule out data hidden with a different bit order, channel choice or encoding. It reads one specific layout. A payload that is bit-reversed, compressed, encrypted, base64-wrapped, length-prefixed, started at an offset, spread over a different channel order or written into a bit other than bit 0 all read as noise here.
It found text. Does that prove something was hidden?
No. Random low bits sometimes spell out eight printable characters by chance, especially in a large image, and both the tool's own description and the report treat a hit as a lead. Judge the find on its content: a readable sentence, a flag format or a recognisable file header is evidence, while eight arbitrary punctuation marks is not. Confirm by carving the bytes out and identifying them.
What is the PNG it gives me?
The bit-plane of the first selected channel, drawn black and white at full size, named after your file with -lsb-plane.png appended. It is the visual counterpart to the text report: eyes catch a block of structure in a plane faster than a printable-run filter does. For any other bit or channel, use Bit-plane viewer.
What does the channels option change?
Which channels contribute to the bitstream, and in what order. rgb, the default, reads red, green and blue from each pixel, giving three bits per pixel, which is the common layout. red, green and blue each read a single channel, one bit per pixel, which is what you need when a payload was written into one channel only. Alpha is never read.
Does it work on JPEGs?
It runs, and the result means little. JPEG is lossy, so the pixel values you get after decoding are not the ones that were saved, and any LSB payload is gone. It is also not the right tool for JPEG-native steganography such as DCT coefficient hiding, which never touches the pixel LSBs at all. Use it on PNG and lossless WebP.