Real tonal banding on images and video: band each color channel or brightness alone, and push the bands toward shadows or highlights.
How to use it
- Open the editor from this page — it loads demo media with the effect already set up — then drop in your own image or video.
- Set the number of levels, then pick a mode: RGB for the classic shifted-color print look, Luminance for clean bands of the original colors.
- Bias the bands toward shadows or highlights, blend with the amount slider, then export a PNG, JPG, or MP4.
What the posterize tool controls
Most posterize tools online run one fixed recipe on a still image: quantize each channel, done. This one exposes the choices that decide the look. The levels slider sets how many tones survive, from a stark two-tone split up to thirty-two. The mode switch picks what gets banded: RGB steps each color channel separately, so colors drift at the step edges, while Luminance steps the brightness and lets the image keep its own palette inside each band. The bias slider then slides the whole band distribution toward the shadows or the highlights, deciding which end of the tonal range holds its detail instead of leaving every step crowded into the midtones.
The amount slider blends the banded result back against the original, so an image can be posterized partway, simplified but not flattened. Everything runs per frame on your GPU: on video the banding is recomputed every frame, so the step edges move with the light instead of sitting on top like an overlay, and the result exports as an MP4 rather than a single frame. The same Posterize effect ships in the Modulate editor, where levels, bias, and amount can all be keyframed, and it stacks with gradient map, halftone, and threshold for full screen-print builds.
Common questions
Is the posterize tool free?
Yes. This page opens the full Modulate editor, free with no signup, with the effect already set up. Anonymous exports run up to 5 seconds at 1080px with a small watermark; a free account exports watermark-free at higher caps, and Pro raises them further.
Does it work on video or just images?
Both. The banding is per-pixel and recomputed on every frame, so drop in an MP4, WebM, or MOV and export the result as an MP4. Most posterize tools online stop at images.
Which mode should I pick, RGB or Luminance?
Luminance keeps your image’s own colors and steps only their brightness, the clean cel-shaded read, and it is the default. RGB bands each channel separately, so hues shift where the steps disagree, worth picking when you want the off-register color of a cheap print.
What does the bias slider do?
It redistributes the bands along the tonal range without changing their count. Slide it negative and the steps bunch in the shadows, keeping dark detail; slide it positive and they bunch in the highlights. At zero the levels are evenly spaced, which tends to spend most of them on the midtones.
Are my files uploaded anywhere?
No. The effect runs in your browser on your GPU. Your media never leaves your computer.
Go deeper
Posterize effect
The posterize effect collapses an image’s smooth gradients into a small number of flat tonal bands, so continuous shading becomes discrete steps. It is named for the poster printing it imitates, where every additional tone meant another pass of ink, and it is the fastest way to make a photograph read as a screen print, a protest poster, or a cel-shaded frame. The fewer the bands, the bolder the result.
Threshold effect
The threshold effect reduces an image to exactly two colors with a single hard cutoff: every pixel brighter than the chosen level takes one color, every pixel darker takes the other. Nothing blends and nothing fades, which is the point. It is the look of stencils, photocopies, and lith prints, the bluntest and most graphic move in image editing.
Gradient map
A gradient map recolors an image by its brightness: every pixel is replaced with the color at the matching position along a gradient you design, darkest tones taking the gradient’s start and brightest taking its end. It is the fastest route to duotones, cinematic two-tone grades, and poster-style color reduction, because you are painting with the image’s own tonal structure.
Dither effect
Dithering renders an image with fewer colors than it really has by arranging the available ones in fine patterns the eye averages back into smooth tone. Where a limited palette would otherwise collapse gradients into ugly bands, dithering trades them for texture: the speckled, crosshatched grain of early computer graphics, GIFs, and one-bit displays. As an effect, it puts that machine-made texture on anything.
There's more where this came from
The full editor lets you use every effect together, over video, text, 3D, and shapes. Free, no signup, nothing to install — it opens with this effect already set up.
Open the editor