How to add music to a video
Adding a soundtrack to an existing video is not something most camera rolls support directly. Here is what does the job.
Adding versus replacing
Adding audio to a video can mean two different things: mixing a new track (music, a voice-over) in alongside the video's existing sound, or replacing the original sound entirely with something else, such as swapping in a licensed song for a clip that had no usable audio.
On an iPhone or Android
The Photos app has no built-in way to add or swap a video's soundtrack. Some social apps (Instagram Reels, TikTok) let you add music at the point of posting, but that only applies within that app, not to a video file you can save and use elsewhere.
On a Mac with iMovie
iMovie can add an audio track: import the video into a project, drag a song or audio file onto the timeline below the video, and adjust its volume or fade. Export when done. This works well but requires building a small project for what might be a one-off edit.
On Windows
Clipchamp (built into recent versions of Windows) supports adding an audio track to a video timeline similarly to iMovie. There is no equivalent in the simpler Photos app video editor.
A direct tool for adding or swapping sound
Stayput's add audio to video tool puts an MP3, WAV or M4A onto a video, or swaps in the audio from another clip, with options to mix or fully replace the original sound, loop a short track to match the video's length, and fade in or out, directly in the browser. The picture is copied over untouched, and nothing is uploaded.
Questions
Can I add music to a video without a full video editor?
Yes, a tool built specifically for adding or replacing audio skips the timeline, transitions and other features a full editor like iMovie or Clipchamp includes.
Can I keep the original sound and add music on top?
Yes, mixing keeps both the original audio and the new track together at whatever relative volume you set, rather than replacing one with the other.
What happens if my music track is shorter than the video?
A tool with a loop option repeats the track to fill the video's length; without it, the audio simply stops early and the rest of the video plays silent or on its original sound.
Does adding audio reduce video quality?
No, a well-built tool copies the video stream unchanged and only adds or replaces the separate audio track.