FL Pixel Art

Prompting for "pixel art" gets you fake pixel art - an image that looks pixel-ish at a glance but has thousands of colors and soft anti-aliased edges when you zoom in. Real pixel art has a small, deliberate palette and hard chunky pixels. FL_PixelArtShader does the honest conversion: it downsamples your image with nearest-neighbor so the pixels are genuinely blocky, then quantizes the colors down to a limited set, optionally snapping them to a palette you provide. The result actually holds up when you inspect it.

Two operations, and they're independent. Pixel size controls how big the blocks are - the spatial chunkiness. Color depth / palette controls how few colors are used - the thing that gives pixel art its retro, limited-hardware feel. You can crank one without the other, but real pixel-art looks come from doing both: big pixels and a tight palette.

The inputs that matter

You feed images, you get an IMAGE out. The controls:

• pixel_size (1–100, default 15) - the size of each output pixel block. Bigger = chunkier, more 8-bit. This is your main knob.
• color_depth (1–255, default 50) - how many color levels to quantize to. Lower = more limited, more retro. This is the second main knob.
• palette_image (optional IMAGE) - feed a reference image and it'll extract a palette from it (via K-means) and map your image onto those colors. This is the pro move: hand it a Game Boy screenshot or a favorite sprite sheet and your render adopts that exact palette.
• palette_colors (2–16, default 16) - how many colors to pull when using a palette image.
• use_aspect_ratio (default on) - keeps proportions sane while downsampling.
• mask (optional) - apply the effect only where the mask allows; invert flips it. blend_intensity and envelope_json let you dial the effect strength or drive it from an external signal.

For a first pass, ignore everything but pixel_size and color_depth. Get the chunk size and palette tightness right, then add a palette image if you want a specific look.

Installing it

Part of ComfyUI_Fill-Nodes. ComfyUI Manager: search Fill-Nodes, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/filliptm/ComfyUI_Fill-Nodes

then restart ComfyUI. No model download for this one.

Getting a good result

The mistake is a huge pixel_size with an untouched color_depth - you get big blocks but hundreds of colors, which reads as "blurry," not "pixel art." Pull the color depth down alongside the pixel size; the limited palette is half the effect. If you're after a specific console-era vibe, the palette_image route is worth the extra wire - matching colors to a real reference is what separates convincing pixel art from a decimation filter. Note the node maps to whatever palette you give it, so a busy reference with a wide gamut won't constrain much; feed it something that already has a tight, characterful palette. And since it processes a batch, it works on video frames too - just keep the settings identical across frames or the palette will shimmer.