The fastest way to shrink a GIF
Size scales with area, not width. Halving both dimensions leaves a quarter of the pixels, and the file usually falls by roughly the same proportion across every frame. No other single change to a GIF does that much.
Which is why, when a GIF has to fit under a limit, resizing is the first thing to try rather than the last.
Where resizing hurts
Shrinking blends neighbouring pixels, and GIF has only 256 colours to represent the result in. On flat graphics that is fine. On a GIF that was already dithered — the speckled look photographic GIFs get — the dither pattern gets blended into mush.
Small text is the other casualty. A screen recording with a code snippet in it becomes unreadable at half size, and no amount of sharpening brings it back.
Enlarging
Possible, and rarely worth it. A GIF is usually already the smallest version of itself that existed; scaling up produces a soft, larger file with no more detail. Find the source video if there is one.
Frequently asked questions
Will it still animate?
Yes. Every frame is resized and the original delays and loop count are kept, so it plays exactly as before, just at a different size.
How much smaller will the file be?
Roughly in proportion to the pixel count. Half the width and half the height means about a quarter of the pixels, and usually a similar cut in bytes.
Why does my resized GIF look speckled?
It was dithered to fit 256 colours, and resizing blends that pattern. Photographic GIFs suffer; flat-coloured ones barely change.
Can I make it bigger?
You can, but there is no extra detail to recover — it will simply be a larger, softer file. Go back to the source video if one exists.
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