The Sound Mixer

Add Audio to Video, Perfectly Synced.

Replace or mix audio tracks in seconds. Add professional background music, crystal-clear narration, or immersive sound effects for free.

How to Add Music to Video

Seamlessly blend or replace audio tracks in five simple steps.

1

Upload Video

Select your video — MP4, MOV, or AVI.

2

Upload Audio

Select your track — MP3, WAV, or AAC.

3

Pick Mode

Choose to Replace or Mix audio tracks.

4

Set Volume

Adjust the volume levels for the new track.

5

Download

Export your finished MP4 video.

Professional Mixing Features

Replace or Mix

Full control over whether to swap the audio entirely or layer it with the original.

Smart Looping

Audio automatically loops if shorter than video, ensuring a consistent soundscape.

Lossless Visuals

We only re-encode the audio streams whenever possible to maintain peak video quality.

Flexible Formats

Supports MP4, MOV, WebM, AVI videos and MP3, WAV, AAC, M4A audio.

Volume Mastering

Precisely adjust the new audio from 0% to 200% for the perfect blend.

Transient Storage

Files are processed in memory and deleted instantly after completion for privacy.

Creative Sound Design

Adding the right audio track can transform a simple clip into a cinematic experience or a professional marketing asset.

  • Replace Bad Audio

    Remove wind noise or unwanted chatter by swapping in clean music.

  • Add Narration

    Combine your tutorial recordings with crystal-clear voiceover tracks.

  • Social Media Prep

    Mix trending music with your original audio for Reels and TikToks.

  • Podcast Clips

    Attach podcast audio to static video backgrounds for YouTube sharing.

Pro Audio Mixing Logic

Our tool uses advanced FFmpeg filters to blend your tracks flawlessly. Replace Mode removes all original audio streams entirely, while Mix Mode uses an amix filter to preserve both tracks.

Volume Balancing

Use the volume slider to lower background music to 20-40% when mixing with speech tracks for a professional finish.

Duration Matching

Don't worry about audio length. We automatically loop short tracks or trim long ones to match your video duration.

Frequently Asked Questions

Popular Conversions

Add Audio to Your Video Now

No registration required. No watermarks. Fast, secure, and works on any device. Start mixing your media today.