About the Add Audio to Video
Add Audio to Video puts a sound file onto your video. Pick any MP3, M4A, WAV, OGG or FLAC file, then choose whether it replaces the video's own sound or plays together with it. Set the volume of the added audio in percent, so background music can sit quietly under speech. If the audio is shorter than the video it repeats, and if it is longer it stops when the video ends. The whole job runs in your browser, so neither your video nor your music is uploaded.
Updated October 2026
How to use the Add Audio to Video
- 1Select your video.
- 2Choose the audio file you want to add.
- 3Pick Replace it to swap the sound, or Play both together to keep the original.
- 4Set the volume of the added audio, then choose MP4 or WebM.
- 5Press Add audio, listen to the preview and download the video.
Replace or mix
Replace it throws away the sound in the video and uses only the file you add. That is the right choice for a silent clip, a screen recording with noisy surroundings, or a slide show that needs a narration. Play both together keeps the original sound and adds the new audio on top, which suits background music under a talking video, or a voice-over over some ambient sound.
Setting the volume
100 percent keeps the added audio at its own level. For music under speech, 20 to 40 percent is usually enough; for a video with no speech, 70 to 100 percent works. The volume can go up to 400 percent for a very quiet recording, but loud peaks may distort, so listen to the preview with headphones before sharing.
- Music under speech: 20 to 40%
- Music over natural sound: 50 to 70%
- A quiet voice-over recording: 150 to 250%
Matching length
The finished video is always as long as the original video. Audio that is too short repeats from its start without a pause, and audio that is too long is simply cut off. A fade out is not added, so choose a track that ends where you need it, or trim it first. A track that loops well, such as a steady beat or ambient sound, works best when it is shorter than the video.
Making a voice-over
Record your narration on a phone or a computer and save it as an audio file, then add it here. Record in a quiet room and speak close to the microphone. If you want to check how the finished video sounds on its own, extract the mixed sound again with Extract Audio from Video. To make the final file lighter, use Video Compressor.
Related edits
If a video already has noisy sound you want to remove first, Mute Video drops it completely. Change Video Volume balances the original sound before mixing. Everything is processed on your device, so keep the tab open until the progress bar is full.
Features
- Adds MP3, M4A, WAV, OGG or FLAC to a video
- Replace the sound or mix both
- Volume control from 0 to 400 percent for the added audio
- Short audio repeats; long audio is cut at the end of the video
- Works on silent videos
- No upload and no watermark
Frequently asked questions
Can I add music to a video that has no sound?
Yes. A silent video simply gets the new audio. Choose Replace it; the mix option needs original sound to mix with.
How do I keep the original sound and add music?
Choose Play both together and set the music volume lower, for example 30 to 50 percent, so speech stays clear.
What if the music is shorter than the video?
It loops from the beginning until the video ends. If you would rather have one clean play, use a longer track, or build a longer file by joining recordings first.
What if the music is longer than the video?
It is cut at the end of the video. If the end sounds abrupt, trim the music to the right length first with Audio Trimmer.
Can I start the music partway through the video?
The audio starts at the beginning of the video. To start later, add a stretch of silence at the start of your audio file, or cut your video into parts.
Which audio files can I use?
MP3, M4A, AAC, WAV, OGG, Opus and FLAC files that your browser can decode. Voice recordings from a phone work well.
Is it legal to use any song I like?
Only if you have the right to use it. Many platforms block or mute videos that use music you do not have permission for, so use your own recordings, royalty-free or licensed music.
Is anything uploaded?
No. The video and the audio file are processed by your browser on your own device.