How to use the Add Audio to Video
- Choose the video.
- Choose the audio file to add.
- Decide whether to keep and mix the original sound, set the new volume and the start time.
- Click Add audio and download.
Background music tips
- Set the new audio to 40% when someone is talking in the video.
- Tick Loop so a short track repeats to the end of the video.
- Use the start time to bring the music in later.
Quality
The picture is copied without re-encoding, so it keeps full quality and the process is fast. The finished video is as long as the original video.
Good to know
The video is copied without re-encoding. The new audio is converted to AAC, optionally delayed, looped and mixed with the original sound, and the result is exactly as long as the video.
Supported files
MP4, MOV, MKV, WEBM, AVI, WMV, FLV, M4V, 3GP, 3G2, MPEG, MPG, TS, MTS, M2TS, VOB, OGV, MXF, ASF, DIVX, F4V, SWF, DV, MOD, TOD, WTV, RM and RMVB video, with H.264, HEVC, VP8, VP9, MPEG-4, MPEG-2, WMV, Theora and other codecs. AV1 videos cannot be read in the browser yet. Files up to 1 GB each.
Frequently asked questions
Can I use music from Spotify or YouTube?
Only use audio files you have on your device and have the right to use. Social platforms may mute videos with copyrighted music.
Is the Add Audio to Video free?
Yes, completely free, with no sign-up and no watermark. Files up to 1 GB each can be converted, and there is no daily limit.
Are my files safe?
Yes. Files are converted locally in your browser and are never uploaded. When you close the page, nothing is left behind.
Does it work on iPhone and Android?
Yes, in Safari, Chrome and other modern mobile browsers. Short files work best on phones; for long or high-resolution videos a computer is faster.