Loop video online

A loop is only as good as its join: the instant the last frame hands over to the first. Our eyes are very good at noticing when something in a scene jumps, and less good at noticing that a scene has repeated. So the trick to a convincing loop is not hiding the repetition but hiding the jump.

Finding a loop point

Find the best loop shrinks a few hundred frames of your clip to tiny grey thumbnails and compares every possible start with every possible end. A good candidate is one where the frame that would come next after the end looks like the start, and where the frames either side match too, so a wave or a swinging lamp keeps moving in the same direction instead of twitching back. The winner is then refined frame by frame at full speed.

The score you see compares the size of that jump with how much your clip normally changes from one frame to the next. A join no bigger than an ordinary frame step is invisible, which is what Excellent match means. A clip that never returns to where it started, like a sunset, can’t produce a clean cut however clever the search, which is where a crossfade comes in.

Cut, crossfade or blend

A Cut plays the frames exactly as filmed. A Crossfade dissolves the last part of the loop into its first part, so whatever is on screen at the end melts into what was there at the start; each pass loses the length of the fade, because those frames now overlap. Blend sits in between: it mixes only a few frames either side of the join, enough to soften a small nudge without shortening anything. Sound follows the picture, with an equal-power fade so the level doesn’t dip.

Why long loops don’t take long

Compressed video stores a full picture every so often (a key frame) and only the changes in between. Because every pass of a loop is identical, loop.video encodes one pass, makes sure it begins with a key frame, and then writes those same compressed frames again with new timestamps for every repeat. An hour of a six-second loop costs six seconds of encoding plus the time to write the file. If you keep a plain cut at the original size and the loop starts on one of the clip’s own key frames, it skips encoding altogether and copies the original frames, so the picture is untouched.

File size

Writing the same frames again doesn’t make the file smaller: each pass still needs its own copy, so size grows with length. As a rough guide, an hour encoded at 1080p and Standard quality lands around 2 GB, and around 1 GB at 720p. Copied frames keep the original’s bitrate, which for phone footage is often three or four times higher, so the estimate under Export settings is worth a glance before a long export. GIF and WebP work differently: they hold one pass and carry a loop instruction, so the player repeats it.