Add Music to Video — Multi-Track Audio Mixer

You can have up to 4 audio tracks total: the original video audio plus 3 additional tracks for music, sound effects, or voiceover.

No. By default we use stream copy for the video track — it stays byte-for-byte identical. Only the audio is re-encoded. You can optionally re-encode the video to a different format or quality.

Yes. Drag the audio clip on the timeline or enter an exact offset in seconds. You can also trim the start and end of each audio track independently.

Enable the "Loop" option in Advanced Settings. The audio will repeat seamlessly until it matches the video duration.

It plays until the last frame, where the video ends. So that it does not stop mid-phrase, the song fades out on its own over the last few seconds — the track's "Fade out" slider shows how long. Set it to 0 for a hard stop, or trim the end of the track so the song finishes earlier.

Only the sound. The picture is stream-copied straight through, so the resolution, bitrate and quality you started with are exactly what comes back — and the export takes seconds rather than minutes, however long the clip is. What gets rebuilt is the soundtrack: up to four tracks mixed down with your per-track volume, offsets, fades and loops.

Once you add music, the tool asks what to do with the video's own sound. Choose “Remove the video sound” and only the music stays in the finished file — its volume goes up to 100%, so the track sounds as loud as the original. Choose “Keep the video sound” and the music plays under the speech and sounds of the clip, which suits vlogs and videos with narration.