GIF Compressor

Keep the Optimisation Level at 3, then raise the Lossy Budget a step at a time and reduce the colour palette to 128 or 64 colours, checking the size after each pass. If it is still too big, resize the dimensions down: an animation stores every frame, so halving the width and height removes about three quarters of the pixels in every one of them. The animation and its timing are kept throughout.

They are two independent Gifsicle features and it matters which one you reach for. The Optimisation Level is lossless: at level 3 Gifsicle stores only the pixels that change from one frame to the next, so a GIF with a static background shrinks a great deal and every frame still looks exactly as it did. The Lossy Budget is not lossless: it lets Gifsicle nudge pixels onto colours their neighbours already use, so the compressor finds longer repeating runs. That is where the big reductions come from, and also where grain and dither speckle appear. Start with level 3 and no lossy, then raise the lossy value until the size fits.

There is no target-size mode for GIF, so it is a short loop rather than one setting: keep the optimisation level at 3, set the lossy budget somewhere around 80, and drop the palette to 128 colours. Check the resulting size against the limit, and if it is still over, either raise the lossy budget or resize the dimensions down — resizing removes pixels outright and is usually the bigger lever on a long animation. How much any of this saves depends entirely on the GIF, so the number on screen after each pass is the only reliable guide.

Yes. Gifsicle works on the GIF file itself, frame by frame, so every frame and its timing survives — this is not a canvas re-draw that would flatten the animation to a single still image. Each result lists the frame count it ended up with, and the split view shows the before and after counts together, because two GIFs playing side by side loop independently and cannot be judged by eye.