Pick 2 to 16 levels per channel and see exactly which colours come out, with their hex codes and how much of the picture each one covers.
Posterizing is how a photo becomes something you can screen print, trace into a vector or print as a bold poster. The page lists every colour in the result so you know how many inks or shapes you are signing up for. It runs on your device; nothing is uploaded.
Drop or click to upload
Drag & drop or paste from clipboard
JPG, PNG, WebP, up to 25 MB
Mode
At most 64 colours (4 × 4 × 4)
Choose, drag, drop or paste a JPG, PNG or WebP up to 25 MB. It is decoded in your browser and never sent anywhere; the line under the upload counts the bytes that leave the page.
Drag Levels per channel between 2 and 16, or switch to Greyscale for a set number of tones. The colour list under the preview updates with each hex code and the share of the picture it covers.
Save a full-size PNG, send it to the vectorizer to trace it into an SVG, or open it in the editor. Copy hex list puts every colour on your clipboard for the print shop.
Every pixel in a normal photo has a red, a green and a blue value, each anywhere from 0 to 255. Posterizing keeps only a few of those values. With 4 levels, each channel can only be 0, 85, 170 or 255, and every pixel is moved to the nearest one. Smooth gradients turn into visible bands, and the picture breaks into flat areas of colour, the look of a hand-cut screen print or a 1960s concert poster.
Because each of the three channels is rounded on its own, the most colours you can end up with is the number of levels cubed. Most photos use far fewer, because a portrait never needs bright green and full blue at once. That is why the readout counts what is really there instead of quoting the theoretical maximum.
| Levels | Values each channel can take | Most colours in colour mode | Tones in greyscale mode |
|---|---|---|---|
| 2 | 0, 255 | 8 | 2 |
| 3 | 0, 128, 255 | 27 | 3 |
| 4 | 0, 85, 170, 255 | 64 | 4 |
| 6 | 0, 51, 102, 153, 204, 255 | 216 | 6 |
| 8 | steps of about 36 | 512 | 8 |
| 16 | steps of 17 | 4,096 | 16 |
Every colour in a screen print is its own screen and its own ink, so the colour count is a cost you pay per shirt run. Greyscale mode is the direct route to a tonal separation: 3 or 4 tones of one ink, each a flat shape the printer can burn to a screen. In colour mode, start at 2 or 3 levels and read the palette: the small colours at the bottom of the list, the ones covering under 1% of the picture, are usually stray edge pixels you can merge in the editor or ignore. Give the printer the hex list from Copy hex list along with the PNG.
A tracer turns areas of one colour into shapes. A photo has thousands of colours, so tracing it directly gives a huge file of tiny slivers. Posterize first and the tracer gets a few large flat regions with clean borders, which traces into a small SVG you can cut, engrave or scale up. Use Trace it to SVG to send the result straight to the vectorizer without saving and re-uploading. Keep dither off for tracing, because a dither pattern is exactly the tiny-sliver detail a tracer struggles with.
For a bold print or a stylised thumbnail, 3 to 5 levels in colour mode keeps the subject recognisable while flattening skin, sky and shadow into graphic shapes. A plain background helps a lot: cut the subject out with the background remover first and only the subject gets posterized, because transparent areas stay transparent here.
Ordered dither adds a fixed 8 × 8 pattern before rounding, so a smooth gradient becomes a fine checker of the two nearest colours instead of a hard band. It does not add colours: the result still uses only the allowed values. It suits pixel art and screen-like looks. Leave it off for printing and tracing, where flat areas are the point. If you want a two-colour dither of a whole photo with your own ink and paper colours, the image effects page does Bayer and Floyd-Steinberg dithers.
Keep going: the posterized image carries over to the next tool with no re-upload.