GIF Optimizer & Compressor

After the colour count, this is the largest remaining lever on file size. Dithering scatters pixels to fake the colours the palette had to drop, which looks smoother but leaves flat areas speckled — and GIF compresses flat areas far better than speckled ones. Smooth is what this tool has always used. Ordered keeps a fine, regular pattern that compresses well. None gives hard colour bands but the smallest file, and often looks best on flat graphics, logos and screen recordings.

A GIF gets one shared palette for every frame. If most of the picture never changes — a screen recording, a caption over a still background — the unchanging area dominates that palette and the moving subject is left with whatever colours are spare. Weighting the palette toward the moving parts fixes that. On footage where everything moves it makes little difference.

GIFs loop forever by default. Playing once suits a GIF that reads as a short clip rather than a background animation. This is stored as a flag in the file, so it changes nothing about the size or the picture.