Merge videos into one
Drop two or more videos, put them in order, and download one MP4 that plays them back to back. Clips from the same phone or camera are copied straight in, which takes seconds and loses nothing; clips that differ are encoded again so they fit together.
The videos appear here once you add some.
The merged video appears here.
How to use it#
- Drop your videos onto the box above, or click it to choose them. More can be added at any time.
- Put them in order with the arrows on each row, and remove any you do not want.
- The videos are merged as soon as the list settles. Play the result in the preview, then download it.
When the clips are copied, and when they are encoded again#
A video track has one setup for its whole length: one codec, one picture size, one way of turning. Clips recorded on the same phone or camera at the same setting share all of that, so their compressed video can be copied into one MP4 one after another, with nothing decoded. That takes a few seconds even for long clips, and the result is exactly as sharp as the originals.
Clips that differ, such as one from a phone and one from a screen recording, or one in 4K and one in 1080p, cannot share a track as they are. Every clip is then decoded and encoded again as H.264 at a high quality, which takes longer, more so for 4K, and loses a little detail that is very hard to see. The page says which it will do before you download.
Size, shape, and sound#
When the clips are encoded again, the result takes the size and shape of one clip: the first, unless you pick another under Size and shape from. A portrait clip in a landscape video, or the other way round, sits in the middle with black bars at its sides, rather than being stretched or cropped. The frame rate is that of the fastest clip, up to 60 frames a second.
Sound that matches in every clip is copied as it is. Otherwise it is encoded again as AAC, and a clip with no sound, such as a screen recording, plays silently for its length so the sound of the clips after it stays in step with their picture. The date and place the first clip recorded are kept in the result.
Frequently asked questions#
Does merging videos lose quality?
#
Not when the clips come from the same phone or camera at the same setting: they are copied as they are. Clips that differ are encoded again at a high quality and at no more than the highest bitrate among the clips, so the loss is very hard to see.
Can I merge a portrait video with a landscape one?
#
Yes. The result takes the shape of the first clip unless you pick another under Size and shape from, and a clip of the other shape sits inside it with black bars, nothing cut off.
How do I change the order?
#
Use the up and down arrows on each row. The list is numbered in the order the clips will play, and the video is merged again once you stop moving them.
Can I merge iPhone videos?
#
Yes, on an iPhone or a computer. Videos from one iPhone at one setting are copied straight in. Choosing them from the Photo Library on an iPhone hands the page converted copies rather than the originals, which merge the same way. The result is saved in the Files app, where it shows under Recents.
How long can the merged video be?
#
The whole result is held in the memory of the tab while it is made, so a merge of more than about 2 GB is too large. At the iPhone's usual settings that is about half an hour of 1080p video, or 12 minutes of 4K. Clips that are encoded again also take a while, longer for 4K, so a long merge of mixed clips is slow.
Why is it slow?
#
Clips from one phone or camera are copied and take seconds; clips that differ are encoded again frame by frame, and that is the slow part. Your file never leaves your device, so the work is done by your own computer or phone, inside this browser tab, not on a server built for it. Every frame is decoded and compressed again: a minute of 1080p at 30 frames a second is 1,800 pictures of about two million pixels each, and 4K has four times as many pixels. The browser hands the compression to your device's video chip where it has one, but each frame still passes through the tab, which shares the processor with everything else that is open. A phone also slows itself down as it warms up, and some browsers slow a tab you switch away from, so keeping this tab in front, closing other tabs, and plugging a phone in all help.
Are my videos uploaded?
#
No. The videos are read and joined inside this browser tab, and the MP4 is handed straight to your downloads. Nothing is sent to a server.