Add Audio to Video Online Free - Replace Video Sound

Add audio to video or replace existing sound for free. Add music, voiceover, or custom audio to MP4 videos. No watermark, 100% browser-based.

Click to upload or drag and drop

VIDEO/* • Maximum file size 500 MB

Click to upload or drag and drop

AUDIO/* • Maximum file size 100 MB

Why Use Toolzilla Audio to Video Tool?

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Replace Audio Track

Replace existing video audio with custom music, voiceover, or narration. Perfect for video dubbing.

🎵

Add Background Music

Add background music to silent videos or replace boring audio with engaging soundtracks.

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Add Voiceover

Add professional voiceover or narration to your videos. Perfect for tutorials and presentations.

🔒

100% Private

Your videos and audio files stay on your device. All processing happens locally in your browser.

No Watermark

Get clean videos with your custom audio. No watermarks, no branding, 100% yours.

💯

Multiple Formats

Support for MP4, WebM, AVI videos and MP3, WAV, M4A audio files. Mix and match freely.

How to Add Audio to Video - 3 Easy Steps

1

Upload Video File

Select your video file (MP4, WebM, AVI, etc.). This is the video that needs new audio.

2

Upload Audio File

Choose your audio file (MP3, WAV, M4A, etc.). This will replace the video's audio.

3

Process and Download

Click "Add Audio to Video" to merge them. Preview and download your video with new audio.

Frequently Asked Questions About Adding Audio to Video

Everything you need to know about replacing video audio with Toolzilla

Frequently Asked Questions

Everything you need to know about this tool