How to Replace the Audio in a Video (and Remove the Original Sound)

Sometimes the picture is perfect and the sound is the problem: wind roaring into the phone mic, a noisy room, a song playing in the background that will get the video flagged, or a voice take you recorded better separately. The fix is to replace the audio track entirely.

Replacing the soundtrack step by step

1. 1Open tools.zenwebx.com/add-audio-to-video and drop in the video.
2. 2Add the replacement audio — a voiceover recording, a clean music track, or the sound from another video.
3. 3Select the part of the audio you need with the waveform handles.
4. 4Under Original sound choose "Remove". The video's own audio is dropped completely.
5. 5Set the start point on the timeline, preview by playing the video, then create and download the MP4.

Syncing a separately recorded voiceover

If you recorded narration separately, the hardest part is getting it to line up. Two tips:

• Trim the silence at the start of your recording with the waveform handles so the audio begins on the first word.
• Drag the audio block until the first word lands where you want it, then play the video to check. Nudge with the "Starts at" box in 0.1-second steps.

Using the sound from another video

You can take the audio track from one video and put it on another — for example, a clean recording from a second camera, or the sound from a public clip you have permission to use. Upload the second video in the audio section, or paste a link from X, Bluesky, Twitch or Pinterest.

What happens to quality?

Nothing happens to the picture. The video stream is copied into the new file exactly as it was. Only the audio is encoded, as AAC at 192 kbps — the standard for MP4 video and good enough for music on any platform.

Just want silence?

To mute a video, add any audio, choose "Remove" for the original sound and drag the New audio slider to 0%. If you only need the audio out of a video instead, use the Extract Audio tool.