# Add Music to Video - Replace Soundtrack Online Swap the audio of any clip for your own music, right in your browser ### Input Files Video MP4 / WebM / MOV New music MP3 / WAV / M4A Convert Clear Replaces the original audio track with your music. Output length is the shorter of video or audio. Processes in your browser (about 100 MB maximum per file). ### Result Preview Your video with new music will appear here ## What does Add Music to Video do? Add Music to Video replaces the sound of a clip with a different audio file and gives you a fresh MP4. It is the quick fix for a video whose original audio is wrong: wind noise on a drone flight, a copyrighted song playing in the background of a family event, silence on a screen capture, or a placeholder track that needs to be swapped for the final licensed one. You choose the video, you choose the music, and the page produces a new file without touching the picture. The soundtrack is replaced locally in your browser. Choose one video and one audio file, then download a fresh MP4 without uploading either source. The tool is designed to preserve the picture while swapping the soundtrack. Results depend on the source format, so use the preview to confirm that the video looks right before sharing it. What it deliberately does not do is mix, duck, or edit audio. There is no volume slider, no fade, and no multi-track timeline. Those jobs belong in an audio workstation or a full video editor. This page covers the common single task, swap the soundtrack, with no account, no watermark, and no upload of your footage. ## How to add music to a video in the browser Replacing a soundtrack takes only a few steps. Prepare the audio first, because this tool applies it exactly as given. 1. **Prepare the soundtrack** Trim your song to the length you need and apply any fade-in or fade-out in an audio editor. The tool will not alter volume or timing, so what you load is what you hear in the result. 2. **Add the video** Click the Video box and pick your clip. The file name and size are displayed when it is accepted. Clips over roughly 100 MB are rejected with a message, so compress or trim large exports first. 3. **Add the music** Click the New music box and pick the audio file. If you want the original dialogue gone before the music begins, remember that this tool already drops the original audio; nothing extra is needed. 4. **Press Convert** The status line shows export progress. Leave the tab open until the download begins. The first job can take longer than later jobs. 5. **Check the preview** Play the preview to confirm the sound begins at the right moment and ends where you expect. If the timing is wrong, press Clear, adjust the audio file, and run again. ## Example: replacing flagged background music on a recap ### Before A small events company has a ninety second recap named venue-recap.mp4. During filming, a radio in the venue played a chart song, and a social platform now flags the upload for copyrighted audio. The team owns a licensed instrumental called warm-open.mp3 that runs two minutes. ### After They load venue-recap.mp4 and warm-open.mp3 and press Convert. Because the song is longer than the video, the output stops at ninety seconds. A few seconds later they receive venue-recap-with-music.mp4 with the same picture and the licensed instrumental underneath, and the platform no longer flags the audio. Had they wanted the music to fade at the end, they would have applied a three second fade-out to the instrumental in an audio editor before loading it, since this tool performs a straight swap. ## Ten situations where swapping the soundtrack helps ### 1. Fixing copyright flags on social uploads Replace an accidental commercial song with royalty-free or licensed music so a post is not muted or blocked. ### 2. Drone and action camera footage Drop wind and propeller noise and lay a calm track under scenic flights, hikes, and rides. ### 3. Silent screen recordings Give a product demo or tutorial capture a light background bed so it does not feel empty. ### 4. Wedding and event highlight reels Replace noisy venue audio with a chosen song or a recorded vow track for a highlight clip. ### 5. Real estate walkthroughs Attach a neutral instrumental to a property tour so listings feel polished across portals. ### 6. Gameplay montages Put a licensed beat over a capture that has only game sound or none at all. ### 7. Product promo clips Add the brand theme to a quick demonstration video before it goes out on advertising channels. ### 8. Classroom and training videos Add a calm background track to slide-based lessons, or replace an old narration with a new recording. ### 9. Birthday and holiday montages Pair family clips with a favorite song to share in a private chat or on a shared screen. ### 10. Testing audio before final edit Try several candidate tracks against a rough cut to see which one fits before committing in a full editor. ## Browser swap compared with editors and cloud services A soundtrack swap can be done in several ways. The right choice depends on how much control you need and where your footage may live. | Consideration | This browser tool | Desktop video editor | Cloud video service | | --- | --- | --- | --- | | Footage location | Stays in your browser | Stays on your computer | Uploaded to a server | | Video quality | Stream copied, no loss | Depends on export settings | Often re-encoded | | Audio control | Straight replacement | Full mixing and fades | Basic to moderate | | Speed | Seconds for typical clips | Render time required | Upload plus processing | | Cost | Free, no account | Free to paid | Free tier with limits | | Best for | Quick one-step swaps | Complex edits | Collaborative web editing | If you need ducking, multi-track mixing, or precise cuts, use an editor. If the job is simply to replace sound on a clip, a stream copy in the browser is hard to beat. ## Things to know before you start - The original audio is replaced, not mixed. Prepare the final audio before loading it. - The output length equals the shorter of the video and the audio. - Each input is limited to about 100 MB because the job runs in browser memory. - The first job can take longer than later ones while the browser prepares the tool. - Only the first video stream and the first audio stream are used. Alternate camera angles or extra tracks are ignored. - Some uncommon source formats may not be handled in the browser. - There is no volume, fade, or trim control; use an audio editor beforehand. - Closing or reloading the tab during processing cancels the job, and you will need to run it again. ## Privacy, licensing, and responsibility Your video and audio are processed in your browser. They are not posted to an encoding API, and the final MP4 goes directly back to you as a download. The page needs an internet connection to load. Closing the tab releases its temporary working data. You remain responsible for the rights to both the footage and the music. Replacing a soundtrack does not remove copyright obligations, and platforms may still act on a track they recognize. ## Frequently Asked Questions ### Does this tool mix my music with the original sound? No. It replaces the soundtrack. The first video stream from your clip is kept, the first audio stream from your music file is attached, and the original audio of the clip is dropped. If you need dialogue and music together, mix them in an audio editor, export one finished file, and load that file as the music here. If you need silence first, run the clip through the Remove Audio from Video tool. ### What happens when the music and the video have different lengths? The output stops at whichever file is shorter. If your song is longer than the clip, the extra music is cut off. If the song is shorter, the video ends when the music ends. To cover the entire clip, use a track that is at least as long, or extend the audio in an editor beforehand. ### Will the video quality drop? The tool aims to preserve the picture while replacing the soundtrack. Some source formats need compatibility processing, so check the preview whenever exact visual fidelity is important. ### Which formats can I upload? Video: MP4, WebM, MOV, MKV, M4V, and AVI are accepted by the file check. Audio: MP3, WAV, M4A, AAC, OGG, FLAC, and Opus. The result is saved as MP4. Common phone and screen-recording clips work best; uncommon source formats may need conversion first. ### Is there a maximum file size? Each file can be about 100 MB. The limit exists because the whole job runs inside browser memory. If your clip is larger, trim it, lower its resolution, or export it at a smaller bitrate before loading it. ### Are my video and music uploaded anywhere? No. The page reads both files locally and returns the finished MP4 as a download. Your source media stays on your device; only the page resources needed for the tool are loaded. ### Why is the first run slow? The first job can take longer while the browser prepares the tool. Later jobs in the same browser generally begin faster. Speed then depends on your device and the source files. ### Can I use copyrighted songs? The tool does nothing to clear rights. Platforms such as YouTube, Instagram, and TikTok scan uploads for copyrighted audio, and a replaced soundtrack that is still a commercial song can be muted, blocked, or monetized by the rights holder. Use music you created, own, or licensed, or tracks released under a license that permits your use. ### Can I control the volume or fade the music? Not in this tool. It does a straight replacement. Normalize, fade, or trim the song first in an audio editor, then load the finished file. Doing it that way also lets you line up a drop or an ending with a scene change in the video. ### How is this different from Music to Photo? Add Music to Video works on a clip that already moves and swaps its sound. Music to Photo starts from a single picture and builds a video around a song. Pick based on whether you begin with footage or with artwork. ## Related video tools - [Remove audio from video](https://www.toolcomb.com/remove-audio-from-video) - Make a silent copy of a clip before adding new sound elsewhere. - [Music to photo](https://www.toolcomb.com/music-to-photo) - Combine one picture and one song into an MP4 when you have no footage. ## Related Tools Discover more free tools that might help with your next task. [Add Music to Photo Still photo + soundtrack → MP4 video Use Tool](https://www.toolcomb.com/music-to-photo) [Remove Audio from Video Mute a video / strip the soundtrack Use Tool](https://www.toolcomb.com/remove-audio-from-video) [Audio Trimmer Cut MP3/WAV clips by start and end time in the browser Use Tool](https://www.toolcomb.com/audio-trimmer) [Audio Joiner Merge multiple audio files into one track Use Tool](https://www.toolcomb.com/audio-joiner) [Audio Converter Convert between MP3, WAV, OGG, and M4A locally Use Tool](https://www.toolcomb.com/audio-converter) [Audio Volume Normalizer Loudness normalize or boost audio volume Use Tool](https://www.toolcomb.com/audio-volume-normalizer) ### Related guides Read the how-to, then come back to this tool when you are ready to run it locally. - [Mute and Replace Audio Track Safely (Browser) Swap narration, add licensed music, or strip room tone with FFmpeg.wasm locally. Sync, ~100 MB per file, first-load engine, and copyright you still owe.](https://www.toolcomb.com/blog/mute-replace-audio-track-safely) [View All Tools](https://www.toolcomb.com/tools)