Filters can shrink files
Mono, noir and duotone collapse the image to a narrow range of colours, so the palette needs far fewer entries — try 32 colours with a mono filter and the file often halves.
GIF filters & colour editor
Give a GIF a look. Pick a filter preset, then fine-tune brightness, contrast, saturation and hue. Filters are applied before the palette is built, so the 256 colours go where they matter.
GIF filters in three steps
Drop the GIF or video.
Try presets; fine-tune with the sliders.
Make the GIF.
Explainer: why GIFs band — the 256-colour palette
Every GIF frame can use at most 256 colours, picked from 16.7 million. The encoder has to choose which ones and snap every pixel to its nearest pick. Drag the slider and watch a gradient sky fall apart into stripes, then switch on dithering to see how scattered pixels fake the missing shades — at a cost in file size.
… for this one frame
What to take away: 64–128 colours is usually indistinguishable for cartoons, UI and screen recordings. Photos with skies or skin need 256 and sometimes dithering. Dithering adds pixel noise, which LZW compression hates, so the file grows.
Questions
Is anything uploaded?
No. All processing happens in your browser tab. Your files never leave your device.