The one thing GIF does that MP4 doesn't
A GIF plays automatically the instant it loads, on every platform, with no play button, no click, and no user interaction required — chat apps, forums, and social feeds treat it like an image rather than a video, which is exactly why it became the format for reaction clips, quick demos, and short looping moments. A video file, by contrast, almost always needs a tap or click to start, even when set to autoplay in many contexts.
That single behavioral difference is the entire reason GIF has survived decades past when better video codecs made it technically obsolete — it's not about quality, it's about the format guaranteeing instant, universal, click-free playback.
The real trade-off: file size and color depth
GIF is a genuinely inefficient format by modern standards — it's limited to 256 colors per frame, which causes visible banding and dithering in anything with smooth gradients or rich color, and it compresses far worse than video codecs, so a GIF of the same clip is often many times larger than an equivalent short MP4 or WebM.
This is why a good conversion tool matters: cropping to a short duration, keeping the frame rate reasonable (10-15fps is often plenty for a looping clip), and reducing the resolution before conversion all keep the output file size manageable — a full-length, full-resolution GIF of anything longer than a few seconds gets enormous fast.
Where a GIF is genuinely the right choice
Reaction clips, short how-to demonstrations in documentation, a quick before/after loop, or anything meant to play instantly inline in a chat or comment thread are all places where GIF's autoplay-everywhere behavior beats a video file's need for a click. If the destination is a platform that treats video differently than images — most messaging apps and forums do — GIF is often the more reliable choice even with the size penalty.
For anything longer than a few seconds, anything where color accuracy matters, or anywhere the platform actually supports smooth autoplaying video (many modern web pages do), a short muted video loop is usually the smarter, smaller alternative.
Getting a clean loop, not just a clip
A GIF that's meant to loop looks best when the last frame flows naturally back into the first — a clip that ends mid-motion creates a visible jump every time it repeats. Trimming to a natural start and end point before converting, ideally where the action has a clean beginning and end, makes a meaningfully better-looking result than just grabbing an arbitrary few seconds.
Keeping the clip short — a few seconds rather than tens of seconds — also keeps file size reasonable and matches what most GIF-consuming contexts (chat, comments, quick previews) actually expect.