Posterize image online
Apply a posterize filter online to create a posterized image or posterized photo. Adjust levels, preview instantly, and download PNG in your browser.
What is a posterize effect?
A posterize effect (also called posterization) reduces the number of distinct color levels in an image by quantizing each RGB channel into evenly spaced steps. Fewer levels produce larger flat color areas and a graphic, screen-printed style; more levels stay closer to a smooth photograph. Use this posterize image tool to set levels, preview beside the original, and download PNG directly in your browser.
Posterize controls
One levels slider posterize filter to reduce colors in photos and graphics.
- Levels 2–64: Pick how many tonal steps each RGB channel uses—the main control for posterized color count.
- Per-channel quantization: Red, green, and blue are posterized independently for vivid banding effects.
- Live preview: Compare original and posterized output side by side as you move the slider.
- Automatic updates: No apply button—the preview refreshes when levels change.
- PNG download: Save as posterize-image.png.
- Client-side only: No account and no server upload.
How to posterize an image
Steps to posterize photo files online.
- Upload your image: Drop or click in the input panel (15 MB max).
- Set levels: Try 4–8 for bold poster art; raise levels for subtler banding.
- Download PNG: Save when the color steps match your poster or social layout.
Tips for posterizing photos
Get better posterized image results.
- Start around 6–10 levels: A mid setting often balances readable detail with visible banding.
- Raise contrast first: Use /change-image-contrast if the posterized output looks muddy.
- Use low levels for logos: Values of 3–5 simplify busy backgrounds behind type.
- Keep the original file: Posterize is destructive—save your source before exporting.
- Pair with sharpen: Light sharpening before posterize can define edges on soft photos.
- Try threshold for 1-bit art: Use /threshold-image when you need pure black and white only.
When to use posterize
Typical uses for posterized images.
- Pop-art portraits: Reduce skin and background tones into flat color regions.
- Screen-print mockups: Preview how a photo might look with limited ink layers.
- Retro game aesthetics: Match 8-bit or 16-color palette vibes on modern photos.
- Social graphics: Make thumbnails stand out with bold, simplified color blocks.
- Album and poster covers: Turn busy gradients into graphic shapes before adding type.
- Stylized UI backgrounds: Simplify photo textures for hero sections without full illustration.
Why use this posterize tool
Benefits of browser-based posterization.
- Simple control: One levels slider maps directly to how many colors remain.
- Keeps hue: Unlike grayscale or threshold, posterize can retain color identity.
- Private: Files never leave your browser.
- Free: Unlimited previews and downloads.
- Instant feedback: Scrub levels instead of re-exporting from desktop filters.
- No install: Works on desktop and mobile with Canvas 2D.
Technical details
How posterize is applied.
- Algorithm: Per channel: bucket = floor(value / (256 / levels)); output = floor(bucket × 255 / (levels − 1)).
- Levels range: 2–64 tonal steps per RGB channel.
- Rendering: Canvas 2D getImageData / putImageData; alpha unchanged.
- Input limits: 15 MB; longest edge 8192 px.
- Related tools: /threshold-image for two-tone output; /grayscale-image for smooth gray only.
- Browser support: Chromium, Firefox, Safari with Canvas 2D.
Frequently Asked Questions
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