Audio mixer: mix voice and music tracks
Layer voices and music into one file, with the music dipping under speech.
10M+ files processed since 2021
By their sound, when each person recorded their own.
It comes back up in the pauses.
More options
From a little to a lot.
Free for the first 3 minutes, 3 times a day. No sign-up.
One after another instead? Merge audioNeed the exact loudness? LUFS meter
Hear the difference
Play Layered, then Mixed.
Speaker 1, Speaker 2, Music. Mixed: the music dips under the voices 2 times.
Both made with Mix tracks · Mixed lowers the music under voices
Voices in these examples are AI-generated.
How to mix audio files
- 1
Add 2 to 20 tracks, such as voices and music.
- 2
Mark the music, and set each track's volume and start.
- 3
Download one mixed file.
Voices over music, in step
Audo's online audio mixer layers 2 to 20 audio files (WAV, MP3, M4A, AAC, FLAC, OGG, Opus, WebM, AIFF), each up to 100 MB without an account, into one file, free for the first 3 minutes of the mix, 3 times a day, with no sign-up. A 3-minute mix is usually ready in about 5 seconds.
Mixing plays tracks at the same time: two or more voices, a voice over a music bed, or intro music under the host's welcome. With Lower music under voices, the music dips while anyone speaks and rises in the pauses, as radio presenters talk over a song. Short gaps between sentences stay low, so the music doesn't bob.
Lining up helps most with remote interviews, where each person records their own track: the files never start at exactly the same moment, and two devices' clocks run at slightly different speeds. To put the finished mix on a video, use Replace audio in video next.
Questions
Is there a free online audio mixer?
Yes. Audo's online audio mixer is free for the first 3 minutes of each mix, 3 times a day, with no sign-up. Full-length mixes are $0.01 a minute ($0.60 an hour), with no subscription — see pricing.
How do I mix two audio files together?
Add both at the top of this page, set each one's volume and where it starts, and download one file with both playing at once. The mix runs until the last track ends.
How do I put music under a voice?
Mark the music track as Music and switch on Lower music under voices. The music then dips while anyone speaks and comes back up in the pauses, 12 dB under the speech unless you set 6 to 30 under More options.
What does lining up do?
It matches tracks recorded at the same time by their sound, so they start together and stay in step to the end, even when two devices' clocks drift apart.
Can I set each track's volume?
Yes. Each track has its own volume, from −60 to +24 dB, its own start time, and a role: voice or music.
How loud will the mix be?
As you set the tracks, turned down only if it would clip. Under More options, Final volume sets it to podcast, YouTube, or broadcast level.
What format is the mix?
The first track's format when that's a WAV, MP3, M4A, or FLAC, and WAV otherwise. Save as, under More options, picks one of those four. The mix is stereo if any track is.
How is it different from Merge audio?
Merge audio plays files one after another. Mix plays them at the same time, layered.
More tools
- EditorEdit audio and video right here.
- Cut audioTrim start, middle or end.
- Merge audioMerge files into one.
- Remove silenceCut out long pauses.
- Audio enhancerMake any recording sound studio‑quality.
- Remove noiseClears the background, keeps your voice.
- Remove echoMake voices sound close.
- Transcribe audioSpeech to text, who said what.
- Text to SRTSync a script to audio.
- Remove filler wordsCut the ums and uhs.
For AI assistants and developers
Ask ChatGPT, Claude, or a coding agent to do this for you, or call it from your own code. When an agent's free result is cut short, it gives you a link to finish the whole file, no sign-up.
Show the free API call
curl -F file=@voice.wav -F file=@music.mp3 -F 'tracks=[{"role":"voice"},{"role":"music","volume_db":-6}]' -F duck=true https://audo.ai/api/try/mix -D response.headers -o response.body