Image Mosaic 🔲
Apply a mosaic pixelation effect to images with adjustable block size.
Click to browse or drop an image here
JPG, PNG, WebPAbout the Image Mosaic tool
The Image Mosaic tool runs entirely in your browser. Drop or select an image, set the Block size slider from 2 to 50 pixels, and click Apply. The tool divides the image into a grid of blockSize × blockSize cells. For each cell, it computes the average RGB color of all pixels within that cell, then fills the entire cell with that average color. This produces a classic mosaic/pixelation effect — larger blocks create a chunkier look, smaller blocks preserve more detail. The averaging uses integer accumulation and divides by the pixel count per block. Nothing is uploaded; all processing is local.
How to use it
- Click the drop zone or drop an image file onto it.
- Drag the Block size slider — larger values produce chunkier blocks.
- Click Apply to render the mosaic effect onto the image.
- Click Download to save, Reset to restore, or Clear to start over.
Frequently asked questions
How is the mosaic color calculated? Each block's color is the arithmetic mean of all pixel RGB values within that block. The block is then filled with this single average color.
What is the output format? The download is a PNG file, preserving detail without compression artifacts.
Does this tool upload my images? No. All processing happens locally in your browser. Your image never leaves your device.
Can I apply the mosaic multiple times? Yes. Each Apply works on the current canvas. However, applying mosaic to an already-mosaicked image won't change much unless you increase the block size. Use Reset to return to the original.