How to merge videos
- Drop two or more videos on the box, or choose them from your device.
- Drag the clips into the order you want. The first picture of each clip is shown as its thumbnail.
- Choose MP4 or WebM and, for clips that need re-encoding, the quality.
- Press Merge, wait for the progress bar, then play the result and download it.
Clips filmed on the same phone or camera with the same settings usually join without re-encoding. For long clips from different sources, expect re-encoding to take as long as the total running time or more.
Questions
Are my videos uploaded?
No. The clips are read and joined by your browser using its built-in video codecs. Nothing is sent to a server.
Why is it fast for some clips and slow for others?
When all clips share the same codec, size, and settings (for example several clips from one phone), their data is copied straight into the new file with no re-encoding. That takes seconds and loses no quality. Clips that differ must be decoded and encoded again, which takes about as long as playing them.
What happens when the clips have different sizes?
The result uses the size of the first clip. Other clips are scaled to fit inside it and black bars fill the rest, so nothing is stretched or cropped.
Which formats can I use?
You can add MP4, MOV, WebM, and MKV files, as long as your browser can decode them. The result is saved as MP4 (H.264 and AAC) or WebM (VP9 and Opus).
What if one clip has no sound?
Silence is added for that clip, so the sound of the other clips stays in sync with their pictures.
Credits
Built on Mediabunny (MPL-2.0) and FFmpeg AAC encoder (via @mediabunny/aac-encoder) (LGPL-2.1-or-later). OneTooling is not affiliated with these projects.