Add audio to video online for free

Upload your video and an audio file, choose replace or mix, and download the result.

Drop your video here

or click to choose · MP4, MOV, WebM

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🔒 100% private: your files never leave your deviceUp to ~200 MB, depending on your device's memory

How it works

Upload your video

Any common video format.

Upload your audio and choose a mode

Replace or mix with the original.

Download

Your video with the new soundtrack.

Replace or mix — what's the difference?

Replacing swaps out the video's original audio entirely with the file you upload — useful for adding a music track to a silent clip or muting an unwanted recording. Mixing keeps the original audio playing underneath and blends in your new track at the volume you choose, useful for adding background music without losing the original sound.

This is a simplified version of the full timeline mixers found in professional editors — there's no fading, syncing to specific timestamps, or multi-track editing, just a straightforward swap or blend that covers the most common case.

Frequently asked questions

Which mode should I use?

Replace if you want to remove the original sound entirely — like adding music to a silent clip. Mix if you want to keep the original sound and blend in something new, like background music under dialogue.

What happens if the audio file is longer or shorter than the video?

The result matches the video's length — a shorter audio file won't be looped, and a longer one gets cut off at the end.