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Add Music to Video

Replace the sound on a video with a track of your own

No sign-up No file limit Nothing uploaded

Add Music to Video

How to use 4 steps
  1. Choose your video under Video file.
  2. Choose a track under Music file.
  3. Set Start the music at and the Volume.
  4. Press Add Music, keep this tab in front, then download the result.

MP4, WebM and MOV. Nothing is uploaded — the file is processed by your own device.

Video with Music

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.

It replaces the original sound, it does not sit under it

Choosing a track means the original audio is never written into the new file at all, which is why there are no levels to balance and nothing to duck — there is only ever one audio source in the result. The [msm_tool slug="video-music"] is deliberately narrower than a real mix for that reason: balancing two tracks properly is a different job, done in different software.

What happens when the lengths do not match

A track longer than the video is trimmed where the video ends, with a short fade-out so it stops rather than cutting off mid-note. A track shorter than the video plays out in full and the remainder of the video is left silent, rather than looping the track back to its start — a loop is almost always more noticeable than a quiet ending, so it is not offered. A track that happens to finish naturally within the video's length keeps its own ending either way.

The real risk here is copyright, not audio quality

A commercial track added to a video that gets posted publicly is a copyright claim waiting to happen, and the usual outcome is the post being muted, blocked or removed after the fact rather than before. The music libraries built into social platforms are licensed for exactly this use; a track from a personal library or a purchased album generally is not, however incidental the use feels.

The start point is worth setting deliberately

Left at its default, playback begins at the very start of the track, and most tracks take fifteen to twenty seconds to reach the part actually worth hearing. A short clip that opens on a track's intro sounds like nothing is happening yet. Finding the section that should play and setting the start point there is usually a better result than leaving it at zero.

Turn it down under a voice-over

Somewhere around thirty to fifty percent volume sits under narration without competing with it. At full volume the music becomes the content rather than the backing, which suits some clips and works against most of them where someone is actually talking over it.

Why this does not work at all in Firefox

MP4 audio needs the AAC codec, and AAC encoding is unavailable in Firefox on every platform and in every browser on desktop Linux. Because writing an audio track is the entire purpose of this tool, rather than an optional extra on top of the video, there is nothing useful it can do where AAC is missing — unlike a tool that merely drops the sound, this one has nothing left to offer. Chrome, Edge and Safari all work normally.

Frequently Asked Questions

Specific to the Add Music to Video. Broader questions about this category are answered on the category page.

No — this replaces rather than mixes. Balancing two tracks properly means levels and ducking, which is a different job. The original audio is not written into the new file at all.
It plays out and the rest of the video is silent. It is not looped, because a repeat is almost always more noticeable than a quiet ending. The page tells you how much will be covered before you start.
It is trimmed where the video ends, with a short fade-out so it stops rather than being cut off mid-note. A track that finishes naturally within the video keeps its own ending instead.
MP4 requires the AAC codec, and AAC encoding is unavailable in Firefox on every platform and in every browser on desktop Linux. Since the whole point of this tool is writing an audio track, it cannot work there. Chrome, Edge or Safari will.
It should not. Music files are usually 44.1kHz and the encoder needs 48kHz, so the track is resampled when it is read rather than played at the wrong rate. If something still sounds off, the source file is worth checking.

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