How this tool works
The original sound is dropped and your music is written in its place. It replaces rather than mixes, which is why there are no levels to balance and nothing to duck — the track you choose is the only thing you hear. Nothing is uploaded; the work happens on your own device.
What the music does depends on its length against the video, and the page says which case applies before anything is encoded. A track longer than the video is trimmed at the end with a short fade-out, so it stops rather than being cut off mid-note. A track shorter than the video plays out and then the rest is silent — it is not looped, because a loop is almost always more obvious than a silence. The start point defaults to the beginning and is worth changing, since the usable part of a track is rarely its intro.
Before you post it
- Music you did not make is still someone else’s: a commercial track on a public post is a copyright claim waiting to happen, and the usual outcome is the post being muted, blocked or removed. The music libraries built into the platforms are licensed for exactly this; a file from your drive usually is not.
- The original audio is gone, not hidden: it is never written into the new file, so there is nothing underneath to recover. Keep the original video if the speech in it matters.
- Set the start point: most tracks take fifteen or twenty seconds to arrive somewhere worth hearing, and a short clip that opens on an intro sounds like nothing is happening. Find the part you want and start there.
- Turn it down for anything with a voice-over: thirty to fifty percent sits under narration without competing. At full volume music is the content rather than the backing, which is right for some clips and wrong for most.