ENPTES

Add audio to a video

Drop a video and an audio file. GustKit uses that soundtrack, copies the picture when the file allows it, and downloads an MP4. Both files stay in this tab.

Runs in your browser Free No sign-up
  1. Choose file
  2. Set options
  3. Get result

Your file never leaves your device. Processed locally in your browser. Nothing is uploaded.

The picture is copied when the file allows it. The result ends when the shorter file ends, unless you loop the audio.

How to add audio to a video

1. Drop the video. 2. Drop the MP3, WAV, M4A or other audio in the second box. 3. Turn on “Loop” only if a short track should repeat until the video ends. 4. Press “Add audio” and download the MP4.

The shorter file wins

Without loop, the result stops when the shorter file ends. A 6 second song on a 1 second video ends with the video. Loop repeats the audio so a long silent clip can keep the music. The old soundtrack is replaced, not mixed.

When the picture is copied

MP4 and MOV often copy the video stream, which is quick. If the container cannot take the new audio that way, GustKit re-encodes the picture. That is slower and uses the same time limit idea as Resize video only if the copy fails. Nothing is fetched from a link.

Frequently asked questions

Can I keep the original sound and add music on top?

Not on this page. The new file replaces the soundtrack. Mix in an editor if you need both.

What if my video has no audio yet?

That is the usual case. Drop any video and the new track becomes its soundtrack.

Which audio files work?

MP3, WAV, M4A, AAC, OGG, Opus and FLAC that fit the size limit on the page.

Are the files uploaded?

No. FFmpeg reads both in this tab.