GIF maker

Different-sized images are the normal case

Most GIF makers fail on a folder of photos, because the underlying tool needs every frame to have identical dimensions and a phone camera does not guarantee that — one landscape shot in a set of portraits and the whole job errors out. Here every image is fitted to a common canvas before anything else happens, either padded to fit or cropped to fill, so a mixed set just works.

The palette is where GIF quality lives

A GIF can hold at most 256 colours per frame. The lazy approach uses a fixed web-safe palette, and it is instantly recognisable: skies band into stripes, skin goes blotchy, and gradients turn to contour lines. What happens here instead is a two-pass job — the frames are analysed to build a palette from the colours actually present, then mapped through it. The difference is not subtle.

Reducing the colour count below 256 is also the fastest way to make the file smaller. For photographs 128 is usually indistinguishable; for screen recordings, line art and anything with flat colour, 64 or even 32 often looks identical and saves a great deal.

Dithering: three real choices

Ordered dithering scatters a fine regular cross-hatch to fake the missing colours, and it compresses better than the alternatives because the pattern repeats. Floyd-Steinberg pushes the error into neighbouring pixels and gives the smoothest gradients, at the cost of a noisier image that compresses worse. None gives flat bands, and for flat-colour content it is both the smallest and the best-looking — dithering a solid background only adds noise to something that had none.

Frame rates a GIF cannot actually store

This is a real and widely unmentioned limitation. A GIF stores its frame delay in hundredths of a second, so a frame rate is only exact when 100 divided by it is a whole number: 10, 20, 25 and 50 fps land exactly, and 12 fps becomes 8 hundredths, which is 12.5 fps. That is why a GIF sometimes runs slightly faster or slower than the number you typed. When your frame rate cannot be stored exactly, the result says what was actually written rather than repeating your number back.

There is a floor too: browsers historically treat a delay under two hundredths of a second as "unspecified" and substitute a tenth, so anything above 50 fps plays far slower than intended. That is a limit of the format rather than of this tool.

Bounce

Playing forward and then backward makes a short clip loop without a visible jump. The turn skips the first and last frames rather than showing them twice, which is the difference between a smooth bounce and a stutter at each end.

Consider not using GIF at all

If the animation is going on a web page you control, an MP4 is typically a tenth of the size and an animated WebP around a third, both with full colour rather than 256. GIF is the right answer when you need something that pastes into a chat window, a document or an email and simply plays — which is a real requirement, and the reason the format refuses to die.