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MP4 audio editing

Add Audio to MP4

Combine an MP4 with music, narration, or a replacement soundtrack while keeping the editing workflow on your device.

Add audio to MP4 Remove original audio

Add sound that fits the MP4 timeline

A useful result depends on both track choice and timing. Decide whether to replace the original soundtrack or mix it with the new audio before export.

01

Choose replacement or mixing deliberately

Replace the original audio when the source sound is unwanted, private, or no longer relevant. Mix tracks when speech, ambience, or another useful element should remain underneath the new music or narration. Preview the balance so neither track masks the important content.

  • Replace audio when the original track should not remain.
  • Mix tracks when dialogue or ambience must stay audible.
  • Use Mute Video first if you need a separate silent MP4.
02

Check duration and synchronization

The added audio can be shorter or longer than the MP4. Review the beginning, transitions, and final seconds to make sure music does not stop unexpectedly and narration matches the picture. Trim the audio or video first when their useful ranges differ significantly.

  • Preview the opening and ending before export.
  • Trim an overly long soundtrack before combining files.
  • Download and play the exported MP4 to verify synchronization.
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How it works

Three steps to finish the browser workflow.

  1. 1

    Choose an MP4

    Open Add Audio to Video and select the MP4 you want to edit.

  2. 2

    Add an audio file

    Choose music, narration, or another track and set how it should combine with the source.

  3. 3

    Export the new MP4

    Preview the timing, process the files, and download the video with its new soundtrack.

Everything you need

Core details about privacy, browser support, output, and practical limits before you start.

Add music or narration to MP4

Choose an audio file that matches the intended MP4 timeline.

Replace or mix the original soundtrack

Replace the source track or mix it with the new audio based on your goal.

Local browser processing and MP4 export

Preview and download the result before discarding either source file.

Frequently asked questions

Quick answers about privacy, output, and practical limits before you start.

Can I add music to an MP4?

Yes. Select the MP4 and an audio file, then use the linked tool to create a new video soundtrack.

Can I replace the original MP4 audio?

Yes. Choose the replacement mode when you do not want the source soundtrack in the exported result.

Are the MP4 and audio uploaded?

No. The linked tool processes supported files locally in your browser.

Related tools

Continue editing with nearby ArtPlayer tools that work with the same browser-first workflow.

Add Audio to Video
Add Audio to Video
Add music or a voice track to a video, then export a new MP4 locally.
Mute Video
Mute Video
Remove the audio track from a video and export a silent MP4 locally.
Trim Audio
Trim Audio
Cut an audio file to an exact range and export MP3, WAV, or M4A locally.
View all tools
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