Image Pixelate, Mosaic & Color Reduction Tool
Select an image, then adjust the "Block size" to control how chunky the pixelate/mosaic effect is and the "Color levels" to control how much the palette is reduced, turning your photo into retro pixel art. Useful for stylizing social media icons and thumbnails, or for mosaic-blurring faces and license plates. If you just need to change the image dimensions, try the Image Resizer & Compressor instead.
🔒 Runs in your browser · Your data is never sent to a server
You can also drag and drop an image file here
PNG is lossless, so the quality setting has no effect (the original transparency is preserved as-is)
How to use
- Choose an image file (drag & drop also works).
- Use "Block size" to set how coarse the pixels are and "Color levels" to set how strongly colors are reduced.
- Compare the before/after previews while you pick the output format and, for JPEG and WebP, adjust the quality.
- Check the result and download it.
Notes
- A larger block size gives a stronger pixelate/mosaic effect and a chunkier, blockier image.
- Fewer color levels means fewer distinct colors are used, giving a retro or illustration-like look. Leaving it at 256 levels (off) applies only the pixelate/mosaic effect and keeps the original colors.
- If you use this to mosaic a face or license plate for privacy, a small block size may still let the original details be guessed. Choose a large enough block size to be safe.
- JPEG has no alpha channel, so transparent areas are filled with white. Use WebP or PNG if you need to keep transparency.
- All processing happens in your browser — the image you select is never sent to a server.
Glossary
Pixel art
A retro, video-game-style look built from individual colored squares (pixels/dots). Turning a photo into pixel art means dividing it into coarse blocks and simplifying the color within each one.
Mosaic (pixelation)
Dividing an image into fixed-size blocks and filling each block with its average color. Larger blocks hide more of the original detail, which is why mosaics are used to obscure faces or personal information.
Color reduction (posterization)
Reducing the number of tone levels used in an image. Rounding each color channel (red, green, blue) to fewer discrete steps turns smooth gradients into visible bands, giving an illustration or retro-game look.
FAQ
What do block size and color count change?
A larger block size makes the mosaic coarser with bigger dots. Fewer colors reduce the palette for a retro, illustrated look. At 256 levels, colors stay unchanged.
Is mosaic safe for hiding faces or license plates?
A small block size can still leak information. When hiding personal data, choose a sufficiently large block size and check the result before publishing.
What happens to transparent PNGs?
Transparency is kept when exporting as PNG or WebP. JPEG has no transparency, so transparent areas are filled with white.
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