Image Splitter
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Add Audio to Video

Add music or speech to a video. Replace the original audio or mix both tracks, adjust their volume, and export the result in your browser.

Video Audio Merger Features

Multiple Audio Clips

Add several audio files, drag to reorder, and trim each clip's start and end. Clips play back-to-back over your video.

Replace or Mix

Replace the original soundtrack entirely, or mix new audio with the existing sound and balance both volumes.

No Re-encoding

The video stream is copied as-is, so merging finishes in seconds with zero quality loss.

How to Add Audio to a Video

1

Upload your video

Select an MP4, WebM or MOV video file. A preview player appears.

2

Add audio clips

Add one or more audio files (MP3, WAV, M4A, OGG). Reorder and trim them as needed.

3

Choose the audio mode

Replace the original sound, or mix the new audio with it and adjust volumes.

4

Merge and download

Click merge. Processing happens in your browser and the video downloads when done.

Real examples

Add Audio to Video · Example 1

These files were processed with this tool or its shared processing code. Compare the source, settings and downloadable results.

Example 1
MP4 + WAV → MP4261.63 Hz400 × 240 px2.45 s

Input2

Source files (2)

ResultMP4

Frames
24
Download 1MP4

Tips for Adding Audio to Video

Preview before you merge

Use the built-in real-time preview to hear exactly how the added audio sits over the video before creating the final file.

Trim clips to hit the beat

Drag the handles on each audio block to cut silence or align a musical drop with the on-screen action.

Duck the original sound

In mix mode, lower the original volume slider and raise the added audio so the music stands out without drowning dialogue.

Mind the video length

The output always matches the video duration. Audio extending past the end is cut off, so position clips within the video timeline.

Extract audio from another video

The audio slot also accepts video files — drop in another clip to reuse its soundtrack without a separate extraction tool.

Compress large videos first

Files up to 500 MB work on desktop (200 MB on mobile), but merging is faster and smoother if you compress oversized videos first.

Real examples

Add Audio to Video · More examples

These files were processed with this tool or its shared processing code. Compare the source, settings and downloadable results.

Example 2
MP4 + WAV → MP4329.63 Hz400 × 240 px2.40 s

Input2

Source files (2)

ResultMP4

Frames
24
Download 1MP4
Example 3
MP4 + WAV → MP4392 Hz400 × 240 px2.38 s

Input2

Source files (2)

ResultMP4

Frames
24
Download 1MP4

Frequently Asked Questions

Selected file contents are processed in your browser without being sent to an application upload endpoint. Loading the site, fonts or processing libraries may still require network requests.
No. The video stream is copied without re-encoding, so quality is identical to the original.
The output always matches the video length. Extra audio is cut off; if the audio is shorter, the remainder of the video is silent.
Video: MP4, MOV (output MP4) and WebM (output WebM). Audio: MP3, WAV, M4A, AAC, OGG, or the audio track of another video file.
The processing engine (about 30 MB) downloads on first use and is then cached by your browser, so later merges start.
Yes. Add as many clips as you need, drag each block along the timeline to position it, and use the handles on both ends to trim. Clips play at exactly the spots you place them.
Choose mix mode, then use the two volume sliders — one for the original soundtrack and one for the added audio. Preview playback in real time until the balance sounds right, for example lowering the original to keep narration clear.
Yes, it runs in mobile browsers like Safari and Chrome. Files up to 200 MB are supported on mobile (500 MB on desktop), so compress very large videos before merging on a phone.

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