Upload an image to posterize
Accepted formats: JPG, PNG, WEBP, BMP, GIF (non-animated)
Paste (Ctrl/⌘+V) or drop an image — or import from a URL
Posterizing an image reduces its smooth range of colors into a small number of flat, solid bands — the bold, graphic look of a screen-printed poster, a comic panel, or 1960s pop art. Image Machine quantizes each color channel to the number of levels you choose: drop it low (2–4) for a striking, simplified poster effect with just a handful of colors, or keep it higher (8–16) for a gentler flattening that still smooths gradients and banding. It's also a quick way to simplify a photo before tracing it into vector art, to cut the color count for screen printing, or to turn a snapshot into a stylized illustration. Everything runs locally in your browser on the HTML canvas — your image is never uploaded, transparency is preserved, and there's no sign-up, no watermark, and no quality loss.
How It Works
Choose a tool
Pick from 120+ tools to resize, convert, compress, or enhance your image.
Upload & edit
Drag and drop your image and adjust the settings. It stays on your device.
Download
Save your result instantly — no watermark, no sign-up required.
Why Image Machine?
Your files never leave your device
All processing runs locally in your browser. Your images are never uploaded to a server.
Completely free
Every tool is free, with no limits, no watermarks, and no hidden costs.
Lightning fast
No upload waiting — your images are processed instantly on your own device.
Professional quality
Pixel-perfect output with full control over format, size, and quality.
Frequently Asked Questions
What does posterize do to an image?
Posterize reduces the number of distinct tones in each color channel, replacing smooth gradients with bold, flat bands of color. The result looks like a printed poster or pop-art illustration. The fewer levels you choose, the more dramatic and graphic the effect.
How many levels should I use?
It depends on the look you want. 2 levels per channel gives the most extreme, high-contrast poster effect (up to 8 total colors). 3–6 levels keep a clearly posterized but still recognizable image, and 8 or more give a subtle flattening that mainly removes gradient banding. Use the Levels slider to preview and dial it in.
How is posterize different from dithering or duotone?
Posterize simply rounds each color to the nearest of a few levels, creating flat bands. Dithering also reduces colors but scatters a noise pattern to fake extra shades, so it looks grainy rather than banded. Duotone and gradient map throw away the original colors and remap brightness onto a chosen color ramp. Posterize keeps your original hues, just with fewer steps.
Is my image uploaded to a server?
No. Posterizing runs entirely in your browser using the HTML canvas, so your image never leaves your device. It works offline once the page has loaded, with no sign-up, no watermark, and no quality loss — and transparent PNGs stay transparent.