Overview
Introduction
This tool pixelates a JPG entirely client-side by averaging pixels within square blocks across the image.
It's a fast way to create a retro mosaic effect or obscure fine detail in a specific area of a photo.
What Is JPG Pixelator?
A client-side JPG pixelation tool that reads an uploaded photo's pixel data, divides the canvas into a grid of equal-sized square blocks, and replaces every pixel in a block with that block's average RGB color.
The block size is fully adjustable, so the effect can range from a subtle softening to a dramatically blocky mosaic.
How JPG Pixelator Works
For each block, the tool sums the red, green, and blue values of every pixel it contains, divides by the pixel count to get an average, then writes that average color back to every pixel position in the block.
Blocks that fall partially outside the image bounds (at the right or bottom edge) are still averaged correctly over just the pixels they actually contain.
When To Use JPG Pixelator
Use it to create a retro 8-bit-style mosaic effect, obscure a background detail casually, or generate a low-fidelity placeholder thumbnail.
It also pairs well with a border or text overlay for a stylized, blocky graphic look.
Often used alongside JPG Blurrer, JPG Area Hider and PNG Pixelator.
Features
Advantages
- Runs entirely client-side; nothing is uploaded to a server.
- Fully adjustable block size for anything from subtle to extreme pixelation.
- Preserves the original image dimensions.
Limitations
- Not a substitute for proper redaction of sensitive information at small block sizes.
- Very small block sizes on very large images can be noticeably slower to compute.
Examples
Best Practices & Notes
Best Practices
- Choose a block size proportional to the detail you want to obscure or stylize - bigger blocks for a stronger effect.
- Preview at full size before downloading, since the mosaic effect can look different when scaled down in a browser thumbnail.
Developer Notes
pixelateJpg iterates the image in blockSize x blockSize blocks, averages RGB per block, and writes the result with a fixed opaque alpha since the final export flattens through JpgPreviewPanel anyway.
JPG Pixelator Use Cases
- Creating a retro 8-bit mosaic effect
- Casually obscuring a background element
- Generating a low-fidelity placeholder thumbnail
Common Mistakes
- Relying on a small block size to fully hide sensitive information.
- Forgetting that block size is in pixels, not a percentage, so the same value looks different on images of different resolutions.
Tips
- Combine with the JPG blurrer for an even softer mosaic look.
- Use a block size that's a clean divisor of the image dimensions for perfectly even blocks at the edges.