Add music to a video
Swap in a soundtrack without touching the picture. Not a single pixel is re-encoded, so it finishes in seconds and loses no quality. The original audio is replaced, not mixed.
Result right hereDrop a video here, or click to choose
MP4 · MOV · MKV · WebM · audio · images · subtitles · ZIP
Nothing about the picture changes when you add music, so nothing about the picture should be re-encoded. Most tools redo the whole video anyway and cost you a generation of quality for it.
Both the video and the audio are copied across byte for byte into a new container. A five-minute clip that would take minutes to re-encode finishes in seconds.
The original audio is replaced rather than mixed in — mixing means decoding both tracks, adding them and re-encoding, which is the slow route this page exists to avoid.
FAQ
Why is it so much faster than other tools?
Because nothing is being encoded. The existing video and the new audio are simply written into a new file.
Can I keep the original sound as well?
Not here. Mixing two tracks means decoding and re-encoding both, which is exactly the cost this page avoids. The full editor mixes properly.
What if the music is longer than the video?
It is trimmed at the end of the video, so the file does not end up longer than the picture.
What if it is shorter?
The rest of the clip is silent. Looping it automatically would be us deciding something you did not ask for.
Does the picture quality change?
Not at all — the video track is copied unchanged.