Add audio to video

Mix or replace a video's soundtrack with an audio file.

Choose a videoor drop it here

MP4, MOV, WebM, MKV, AVI, or M4V

About Add audio to video

Add Audio to Video mixes a new audio file into a clip's existing soundtrack, or replaces that soundtrack outright. Levels are fixed, and the export ends with the shorter stream.

Runs entirely in your browser. Your files never leave your device.

How to use it

1.Add the video and the audio, compare their lengths, and decide whether they really should start together.
2.Turn on Replace original audio to drop the video's own sound, or leave it off to hear both.
3.Render it, watch the whole thing with sound, and check the dialogue still cuts through.

Options

Replace original audio puts only the new track into the result.
Mixing keeps both tracks at fixed levels, and there are no per-track volume controls.

Limitations

There is no delay, no gain, no time-stretch. It will not line speech up with lips for you.
Two loud sources at fixed levels can clip or bury the dialogue. Sort the levels out in the source files first.

Common questions

What if the audio is shorter than the video?

The export stops with the shorter stream, so it can end early. Match the durations first if the whole video has to survive.

Can I start the new audio later?

Not here. Add the silence you need to the front of the audio file before you bring it in.

Next stepNormalize loudnessGet the added track to a predictable loudness before the next mix.