Is my audio uploaded anywhere?
No. Everything runs inside your browser tab, and the result is created on your device. Nothing is sent to a server.
Podcast hosts want MP3, editors want WAV, and a phone recording arrives as M4A or Opus. This converter reads almost any audio format and writes the five that matter, with quality settings that make sense for speech.
It uses ffmpeg compiled to WebAssembly. The file is processed on your device and never uploaded.
How to use it
Choose a file
Drop an audio file (up to 500 MB) onto the box or pick it from your device. MP3, WAV, M4A, AAC, OGG, Opus, FLAC and most others work.
Pick a format and quality
MP3 is the safe default. For lossy formats choose High, Standard or Small, and tick mono if the recording is a single voice.
Convert and download
The tool shows the size before and after. Play the result if you like, then download it.
Which format to choose
| 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 | Lossless, about half the size of WAV. |
| WAV | Editing | Uncompressed and large. |
Good to know
- Convert from the best source you have. Turning a low-bitrate MP3 into a higher bitrate does not bring detail back.
- Convert once, at the end. Every lossy conversion loses a little quality.
- For a single voice, mono halves the file size at no audible cost.
- 192 kbps MP3 or 96 kbps Opus is plenty for speech.
What happens to your file
The file is read and processed by your browser using ffmpeg compiled to WebAssembly, and the result is written back as a download. It is not sent to Airtape or any other server, and it is not stored. You can check this in your browser's network tab: no request carries your file.
The converter engine is about 30 MB. Your browser downloads it the first time you convert a file and then keeps it, so later runs start right away. Files are limited to 500 MB because a browser has limited memory.
Credits
This tool is built on open-source software. Its source code and license are available at the links below.
- FFmpeg — The audio engine, licensed GPL-2.0-or-later.
- ffmpeg.wasm — FFmpeg compiled to WebAssembly. Source code and license are available there.
Frequently asked questions
Which formats can it read?
Nearly everything ffmpeg understands: MP3, WAV, M4A, AAC, OGG, Opus, FLAC, WMA, AIFF and the audio of most video files.
Why is the first run slower?
The first time, your browser downloads the converter engine, about 30 MB. After that it is cached and later runs start right away.
Will converting reduce the quality?
Converting to a lossy format such as MP3 loses a little quality, which is why the tool offers quality levels. WAV and FLAC keep what is in the source.
Is there a file size limit?
Yes, 500 MB per file, because a browser has limited memory.
Further reading
Free video to audio converter
Pull just the sound out of a video recording.
Free silence remover
Shorten long pauses and dead air in your episode.
How to record your first podcast
From setup to a finished episode.
Podcast recording with Airtape
Local tracks per guest, so the call quality never ends up in the file.