Pixelize

One slider, one idea: make your image look like it was rendered at a tiny resolution and stretched back up. Pixelize does the thing that's been used in every game, movie and video since the 80s to say "this is retro" - it turns a smooth render into chunky visible pixels. It's the simplest node in this pack, and it's also one of the least missable: there is exactly one input and it does exactly what it promises.

How it works

The image is downsampled with average pooling - each block of pixel_size × pixel_size pixels becomes a single pixel holding the block's mean color - then stretched back up to the original resolution with nearest-neighbor sampling. Average pooling is the important detail: unlike naive nearest-neighbor downscaling, it actually averages the colors inside each block, so you don't get aliasing or blown-out highlights at the block edges. It's the same technique used to fake low-res in a million "pixelate" tools, done correctly.

• pixel_size (2–128, default 8) - the size of the resulting pixels in image pixels. 4–8 gives a tasteful "lower resolution" retro look; 16+ starts to look like intentional pixel art abstraction; 64+ is a mosaic. Minimum is 2, which is basically the original image.

Output is a single IMAGE, same dimensions as the input.

Install

Pixelize is one of ~22 nodes in ComfyUI-post-processing-nodes.

• ComfyUI Manager: search "post processing nodes", install, restart.
• Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/EllangoK/ComfyUI-post-processing-nodes

Restart after. No requirements.txt or downloads - avg_pool2d plus interpolate, both stock torch. It's under postprocessing → Effects in the node menu.

Using it

The common pattern is chaining: Pixelize followed by a slight blur or the pack's Sharpen at low alpha, which softens the block edges into something that reads as "intentionally lo-fi" instead of "broken render." It also pairs naturally with the pack's Quantize - pixelate the geometry and quantize the palette and you've got a full retro-game look in two nodes. One thing to know: the output stays at full resolution, so you're not actually saving any file size - this is purely cosmetic. And like everything in this pack, it runs per-frame on the CPU, so a video batch at pixel_size 4 will take a moment.