How to Use Add Audio to MP4
- Upload your MP4 video file
- Upload the audio file you want to add
- Click Process to combine video and audio
- Download the MP4 with the new audio track
Features
- Add any audio file (MP3, WAV, AAC) to an MP4 video
- Replace existing audio or add to a silent video
- Option to loop video to match audio length
- No upload — processing runs in your browser
Frequently Asked Questions
- How do I add audio to an MP4 file?
- Upload your MP4 video and your audio file, then click Process. The audio is merged with the video and you can download the result.
- Will the existing audio be replaced?
- Yes. The tool replaces the video's original audio track with your uploaded audio file. To keep the original audio, use the Mix Audio tool instead.