Images or video: which should you start from?
Start from images when you already have the individual frames: a set of product photos, a before/after pair, hand-drawn animation cells or screenshots of a process. Each image becomes one frame, and you decide exactly how long it stays on screen. For a single-format batch you can also use the dedicated JPG to GIF or HEIC to GIF converters.
Start from video when the motion already exists — a reaction clip, a screen recording or a phone video. The maker samples the clip at the frame rate you choose (10–15 fps is ideal for most GIFs). For clips longer than 30 seconds, switch to the Long GIF Maker; to capture something happening on your screen right now, use the GIF Recorder.
How to make a GIF that looks good and stays small
GIF stores at most 256 colours per frame and compresses far less efficiently than modern video, so size is driven by three things: pixel dimensions, number of frames and how much changes between frames. Keeping the width around 480 px and the frame rate at 10–15 fps gives a sharp, smooth GIF that usually stays under a few megabytes.
Once you have your GIF, you can fine-tune it with the other tools: crop away borders, add a caption, change the speed or run it through the GIF compressor if it needs to fit an upload limit.