Make a video longer

People usually need a longer video for a reason with a number attached: an upload form or ad slot that asks for a minimum duration, a voice-over that runs 47 seconds, a song that lasts two minutes and twelve, or a slot in a presentation. With Length, you give the number and the tool works out the passes. A 7-second clip set to one minute plays eight full times and then 4 seconds of a ninth pass, so the file stops at 1:00 exactly.

• Check the target before exporting: the estimate line under Export settings shows the final length beside the file size.
• When a song sets the length, Until the music ends saves the measuring. Choose a track with Choose music, trim it with Music start and Music end, and the video runs exactly as long as the trimmed song. More on that in loop a video with music.
• If you would rather think in plays than seconds, Number of times is covered on the repeat video page.

For long targets, from ten minutes up to the three-hour maximum, see loop a video for an hour, which goes into file sizes.

Looping is one of several ways to add time to a clip. loop.video only loops; it does not change speed, freeze frames or add text. The other three methods are done in a timeline editor, and it helps to know which one suits your footage.

Loop the clip (this tool)

Motion stays at normal speed and nothing is invented, so the extra time looks like more of the same. It works best on footage without a clear start and finish. The weak point is the join: if the last frame differs a lot from the first, viewers see a jump each pass, which a crossfade or a better loop point usually fixes.

Slow it down

Playing at half speed doubles the length with no repeats. Movement looks slower and heavier, which suits sport or splashing water but looks odd on people talking. Unless the editor corrects it, slowed sound drops in pitch, so many people mute it. Smooth slow motion also needs footage shot at a high frame rate; normal footage slowed a lot can look jerky.

Hold the last frame

A freeze at the end adds time without repeating anything and fits a clip that finishes on a strong image, such as a product shot. Held for more than a few seconds it starts to look like the video has stalled.

Add a title card or end card

A few seconds of text before or after, such as a title, a caption or a call to action, adds length and information at once. It is the best choice when the clip is meant to stay short and the extra time has a job to do.

These can be combined. A common approach is to loop the clip here to most of the target length, then add a short end card in your usual editor.

• Let Find the best loop choose the frames. It compares frames across the clip and rates the join from Excellent to Poor match, with a percentage. Set Shortest loop higher if it keeps picking a section that is too brief.
• A Crossfade dissolves the end into the start. It hides most jumps, but each pass gets shorter by the Crossfade length; with Length chosen, the tool still fills the target time.
• Blend mixes one to six frames either side of the join to soften a small jump without changing the length of a pass.
• Keep Smooth the sound at the join on so the audio does not click each time the loop restarts.

Some clips cannot be made to repeat invisibly, because the scene never returns to where it started. The seamless loop video page explains what makes footage loop well.