Online Video Editor

Trim, cut and join clips, build an animation from stills, lay a soundtrack over it, then save a real MP4

Material

Drop video, stills or sound here or click to choose them — clips, a run of JPEGs to make an animation, and an MP3 or WAV to lay over the whole thing
Files are read straight from the disk and never leave the browser — nothing is uploaded and no account is needed. Long clips are read as they play, so a very large file costs time rather than memory. A batch of pictures dropped together becomes one run of stills in the order their names sort, and a sound file becomes the one soundtrack laid over the whole film.

The edit

A piece runs from its start to its end, and the pieces play in the order shown. To cut something out of the middle, split the piece where the unwanted part begins and delete the half you do not want. Each piece shows the frame it opens on, and its own play button runs that piece by itself, sound and all.

Preview

0:00.0 / 0:00.0
The preview is framed exactly as the finished file will be, so what the bars and the crop do to a shot is visible before anything is written. Space starts and stops it; the arrow keys step a frame at a time, or a second at a time with shift held.

The finished file

A resolution names the short side of an upright shape and the tall side of a wide one, so 1080p is 1920×1080 lying down and 1080×1920 standing up.

Save it

The sound of an ordinary clip is read straight out of the file and compressed as fast as the machine will go, so keeping it costs almost nothing. Only a clip too long to hold in memory has to be listened to as it plays, and that one is read at its natural speed. A run of stills has no sound of its own, so a soundtrack laid over the film is what fills it.

About editing video in a browser

For most of the medium's history, cutting film meant a room full of equipment and, later, a desktop application heavy enough to need its own machine. What changed is not that video became simpler but that the ordinary browser grew the parts a cutting room needs: it can now decode a moving picture, hand the individual frames to a page, and compress new ones back into a standard file. A trim that once meant installing software and waiting for an upload is now a page you open and close. The same machinery serves a trick older than film itself: a run of separate pictures shown quickly enough reads as movement, which is how animation worked for decades before anyone could record a moving image at all.

The vocabulary is worth knowing, because it is the same everywhere: resolution counts the lines in the picture — 1080p, 1440p, 4K — and governs how much detail survives. Aspect ratio is the shape of the frame, and it is a stronger choice than it looks: 16:9 is the shape of televisions and most of the web, 9:16 belongs to the phone held upright, 21:9 is the wide cinema frame, 4:3 is the shape of everything shot before the mid-2000s, and 1:1 is the square that social feeds settled on. Putting a shot into a frame it was not filmed for means either accepting bars along two edges or cropping away part of the image, and there is no third answer. Frame rate is the third figure: cinema settled on 24 pictures a second, television on 25 or 30, and anything from about 15 upward still reads as motion rather than as a slide show, which is why a run of photographs shown quickly enough becomes an animation.

Two habits save more trouble than any tool. Cut for the audience rather than for the footage: the interesting part almost always starts later and ends earlier than the raw clip does, and a ruthless trim is usually the single biggest improvement available. And decide the destination before exporting rather than after, because every platform has a shape and a size it prefers, and a file made for the wrong one gets re-compressed on arrival — which is where sharp footage quietly turns soft. Sound deserves the same forethought as the picture: a join that looks abrupt usually sounds worse than it looks, and a piece of music running underneath will carry a sequence further than any amount of fussing with the images above it.