GIF Maker

Combines several images into a GIF in list order: one image per frame, with append, remove, replace and insert-at-position; each frame's duration can be set individually, or changed all at once with the batch field (default 100ms, minimum 20ms).

Output size has three modes: Auto takes the widest and tallest frame and centres every frame in it — no scaling, so mismatched sizes leave transparent margins; First frame and Custom actually rescale, with a choice of proportional fit (contain, keeps aspect ratio and leaves margins) or stretch (fills the box and distorts). Remember that Auto never scales: drop one oversized image into the list and the whole GIF balloons to that size.

GIF allows 256 colours, so frames are quantised with median cut down to 255 colours, plus one transparent slot when any pixel has zero alpha. The cost is banding on gradients and photos, and because each frame is quantised independently, playback can show slight flicker when neighbouring palettes differ. For smooth transitions, build frames from flat colours or simple shapes — or use a video format.

Three hard limits: at least 2 and at most 60 frames; total pixels (width × height × frames) must stay under 7 million or the build is refused; looping can be infinite or play once. Delay uses GIF's 1/100 second units, but browsers generally treat anything below 2 (20ms) as 100ms — hence the 20ms floor. To go faster, drop frames or reduce size; typing 10ms accomplishes nothing.