Quantize Image
Reduce a picture to a palette of 2 to 256 colours with an adaptive palette and optional dithering, and save it as PNG, GIF or WebP.
or browse filesdrop an image here or paste
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Reduce a picture to a palette of 2 to 256 colours with an adaptive palette and optional dithering, and save it as PNG, GIF or WebP.
or browse filesdrop an image here or paste
Colour quantization takes a picture with millions of colours and rebuilds it from a small palette - the way GIF and 8-bit PNG store images, and the reason old game and web graphics look the way they do. This image quantizer computes the palette from the picture itself: drag the Colours slider from 2 up to 256 and an adaptive palette is fitted to the image, so a sunset keeps its oranges and a forest its greens instead of being forced through a fixed set. Use it to reduce the number of colours before saving an indexed file, to make a flat poster-style version of a photo, to match sprite or pixel-art limits, or simply to see what a picture looks like in 16 colours. The i-button on the stage shows the palette and the colour counts before and after.
With Dither set to None each pixel takes its nearest palette colour, which gives flat bands - clean for logos and posterized looks. Floyd-Steinberg spreads each pixel's rounding error into its neighbours, so a few colours can fake many more; it is the classic GIF look and keeps gradients smooth at 16 or 32 colours. Ordered dither uses a fixed 8 by 8 Bayer pattern instead, the regular crosshatch of retro screens and printing, and it stays stable frame to frame in animations. The Greyscale switch quantizes to grey levels rather than colours - 4 greys for a stark newsprint effect, 16 for an old display.
PNG keeps the quantized pixels exactly, and a picture with 256 or fewer colours compresses well. GIF stores the same palette as an indexed file with the exact colours, which is what most quantized graphics are for. WebP and JPG are also offered, though JPG will blur the hard colour steps a little. Copy puts the result on the clipboard, and Share on a phone hands it to a chat or a post.
The k-means palette, the pixel mapping and the dithering all run in the browser's own canvas on your device. The picture is never uploaded, there is no queue and no server-side copy, and a 12-megapixel photo quantizes in well under a second on a laptop.
It is the step that turns a true-colour image, where each pixel can be any of 16 million colours, into an indexed image whose pixels point into a short palette. Fewer colours mean smaller indexed files and a distinctive flat look. The quality depends on how well the palette is chosen, which is why this tool derives it from the picture rather than using a fixed one.
256 is the GIF and PNG-8 maximum and usually looks close to the original with dither on. 64 or 32 is a good compromise for icons and sprites. 16 and 8 give a visibly reduced, poster-like image, and 2 makes a two-tone graphic. Try Floyd-Steinberg when a low count looks banded.
The palette never holds more colours than the picture can use. A flat graphic with six colours quantized to 256 will still show six, and the details card reports the real number. On a photo the full count is used.
Yes. Transparent pixels stay transparent in PNG, WebP and GIF; only the opaque colours are counted toward the palette. Choosing JPG flattens the image, as JPG has no alpha channel.
No. Every calculation runs locally in the browser, and the download is built in your device's memory. The picture never leaves it.