Free tool
Mix several audio tracks into one file, right in the browser
Load the host, guest and music tracks, set a volume for each one and save the mix as MP3 at 192 kbps, or as M4A, Opus, FLAC or WAV. Everything runs on your device, nothing is uploaded.
Your file never leaves this browser tab. Nothing is uploaded.
Drop audio files here
MP3, WAV, M4A, OGG, FLAC, WebM and more. Up to 500 MB per track, 8 tracks at most.
Separate tracks in, one mix out
A remote recording gives you one track per person. This mixer sums them into a single file: load every track, balance the volumes, mute a track that should stay out, and download the finished mix in the format you want.
It uses ffmpeg compiled to WebAssembly. The files are processed on your device and never uploaded. MP3 at 192 kbps is the default, which is a good publishing quality for speech.
How to use it
#howLoad your tracks
Drop up to 8 audio files (500 MB per track) onto the box or pick them from your device. Host, guests, intro music and a video's sound all work.
Balance the tracks
Set a volume for every track and mute any track that should not be in the mix. The mix always lasts as long as the longest track, and a limiter keeps the sum from clipping.
Choose the format and mix
MP3 at 192 kbps is ready to publish. Pick a higher quality, a smaller file or a lossless FLAC or WAV if you keep editing, then mix and download.
Which format to choose
#formats| Format | Best for | Notes |
|---|---|---|
| MP3 | Publishing a podcast | Plays everywhere. 192 kbps is a good default for speech. |
| M4A (AAC) | Apple devices and podcast apps | A little smaller than MP3 at the same quality. |
| Opus | The smallest files for speech | Some older players cannot open it. |
| FLAC | Archiving and editing | Lossless, about half the size of WAV. |
| WAV | Editing | Uncompressed and large. |
Getting a good mix
#tips- Start with every track at 100% and lower the louder ones first. Raising a quiet track also raises its room noise.
- Tick the loudness option to bring the finished mix to -16 LUFS, the podcast target, in the same run.
- Shorter tracks simply end in the mix: the longest track sets the length, and nothing is stretched.
- Mix at the end, once. Every lossy save loses a little quality, so keep a FLAC or WAV if you plan to edit further.
What happens to your files
#privacyThe files are read and processed by your browser using ffmpeg compiled to WebAssembly, and the result is written back as a download. They are not sent to Airtape or any other server, and they are not stored. You can check this in your browser's network tab: no request carries your files.
The mixing engine is about 30 MB. Your browser downloads it the first time you mix a file and then keeps it, so later runs start right away. Tracks are limited to 500 MB each because a browser has limited memory.
Credits
#creditsThis tool is built on open-source software. Its source code and license are available at the links below.
Frequently asked questions
No. Everything runs inside your browser tab, and the mix is created on your device. Nothing is sent to a server.
Up to 8 tracks in one mix, each up to 500 MB. The mix lasts as long as the longest track.
MP3 at 192 kbps is the default and is ready to publish. FLAC or WAV are lossless and better if you keep editing afterwards.
It normalizes the finished mix to -16 LUFS, the loudness Apple Podcasts and most hosts expect, and keeps peaks below -1 dB.
The first time, your browser downloads the mixing engine, about 30 MB. After that it is cached and later runs start right away.
Further reading
Record every guest on a separate track
Airtape records every guest locally on their own track, ready to mix. Free to start.