Make a seamless loop video

Your eye notices a loop at the instant something changes faster than it should. If the frame that follows the last one is only as different from it as any two neighbouring frames, nobody can tell where the clip begins. Four things decide whether that happens.

Matching frames

The picture at the end has to be close to the picture at the start: the same leaves in the same places, the same wave about to break, the same flicker of a flame. Repetitive motion such as a spinning fan, steady rain or a ticking pendulum gives you many near-identical moments to choose from.

Motion heading the same way

Two frames can look alike while things in them move in opposite directions. A swing at the top of its arc looks the same on the way up and the way down, and joining those two moments makes it stop and turn round. A good join matches the frames just before and just after as well, so motion carries straight on.

A camera that does not move

Handheld drift and slow pans are the most common reason a loop jumps. Even a few pixels of shift between the end and the start makes the whole frame twitch at the restart. A tripod, or resting the phone on something solid, removes the problem at the source.

Steady light

Brightness that creeps up or down across the clip, from a cloud, a sunset or the camera adjusting its own exposure, produces a visible step at the join even when the motion lines up. Lock exposure if your camera allows it, and avoid shooting as the light is changing.

The search looks at a spread of frames from the whole clip, shrunk to a tiny grid of brightness values. For every possible pair of start and end it measures how far the frame after the end differs from the start frame, and it also compares the frames on either side of the join so that motion has to agree in direction. It then checks the frames close to the winning pair one by one, so the handles land on exact frames rather than on the nearest sampled one.

Rather than using a fixed threshold, the score is measured against the clip itself. The tool works out how much a typical frame differs from the next in your footage and asks how big the jump at the join is compared with that ordinary step. A busy scene with rippling water can hide a bigger jump than a still interior can, and the rating reflects that.

• Excellent match: the join is about the size of a normal step from one frame to the next, so it should be invisible with a plain Cut.
• Good match: the jump is up to roughly twice a normal step. Most viewers will not notice it; a short Blend or crossfade removes any doubt.
• Fair match: up to about four times a normal step. Expect a visible flick with a cut. The tool suggests Use a crossfade, and that is usually right.
• Poor match: nothing in the clip comes back close to where it started. A crossfade will still turn the jump into a dissolve, but it cannot make it disappear.

The percentage tells the same story on a finer scale: it is 100 when the join is no bigger than an ordinary frame step and falls as the jump grows. Among joins that score equally well, the search prefers the longer loop, and Shortest loop stops it from settling on a tiny fragment.

Know its limits. It compares brightness patterns, so a change in colour alone barely registers, and fine detail is averaged away in such a small grid. It also cannot invent a loop in footage that never returns to a similar state, such as someone walking out of shot. Treat the rating as a strong hint and let Watch the join have the final word.

• Cut jumps straight from the last frame back to the first. It is the right choice for an excellent match, for anything with sharp detail such as text or faces, and when you want every frame left untouched. It is also the only join that, with Shape and Size left at original, Quality on Standard and a loop that starts on a key frame, lets the export copy the original frames without re-encoding.
• Crossfade dissolves the final moments of the loop into its opening moments, and the sound crossfades along with the picture. It suits water, smoke, clouds, fire and foliage, where a soft overlap reads as natural movement. Each pass gets shorter by the crossfade length, because that stretch overlaps the start. Long crossfades on fast or sharp-edged motion can show a faint double image, so keep it brief there; 0.3 to 1 second covers most clips.
• Blend mixes 1 to 6 frames on each side of the join, leaning the end towards the first frame and the start back towards the last. The loop keeps its full length. Use it for a good match that still has a tiny flick, such as a slight brightness step, where a full crossfade would be more than the clip needs.

A practical order: run the search, try Cut and watch the join; if you see a flick, try Blend at two or three frames; if that is not enough, switch to Crossfade and lengthen it until the jump turns into a gentle dissolve.

• Use a tripod or prop the camera on something solid. No amount of joining can hide a frame that has shifted.
• Lock focus and exposure before you record, so the camera does not hunt or brighten partway through.
• Record far longer than the loop you need. Thirty seconds of a fountain gives the search hundreds of moments to pair up; five seconds may give it none.
• Choose subjects with cycles: waves, rain, a fountain, flickering flames, a rotating sign, traffic lights, a breathing pet asleep.
• Keep the edges of the frame clear. A person or bird crossing the edge near the end of your clip has to be out of shot at the start as well.
• Avoid scenes where the light moves, such as clouds passing over a sunny view or shadows sliding during sunset.

For long calming loops of a fire, rain or the sea, the ambient video loop page goes further into what makes footage relaxing to watch on repeat.

Audio gives a loop away faster than pictures do. A sudden cut in the waveform produces a click, and a sound that stops mid-word or mid-note announces the restart even if the image is perfect.

• With Sound set to Original and a Cut or Blend join, Smooth the sound at the join (on by default) blends the last moment of sound into the first so there is no click.
• With Crossfade, the sound crossfades together with the picture at every join.
• If the clip has speech or a distinct noise near the end, move the handles so the loop avoids it, or choose Off for a silent export.
• With Music, your song replaces the clip’s own sound, so the picture join is the only one that matters. Until the music ends fits the loop to the song’s length; see loop a video with music for the details.