Free Audio Converter
Audio Converter turns audio files, or the sound of MP4, WebM and MOV videos, into MP3, M4A (AAC), Opus, FLAC or WAV. Pick the bitrate or a 16- or 24-bit depth, change sample rate or channels, normalize, and apply one trim to every file. A whole batch can be downloaded as a ZIP.
- Output:
- MP3, M4A, Opus, FLAC, WAV
- MP3 bitrate:
- 64–320 kbps, constant
- M4A (AAC):
- Not in Firefox or Chrome on Linux
- Price:
- Free
- Runs:
- Locally, in your browser
- Uploads:
- None: files never leave your device
- Account:
- Not needed
Quick answers
Are my files uploaded?
No. Decoding and encoding happen in your browser, so your audio never leaves your device.
Why is M4A (AAC) not available?
AAC encoding comes from the browser (WebCodecs). Chrome, Edge and Safari on Windows, macOS, Android and iOS include it; Firefox and Chrome on Linux do not. Opus or MP3 work everywhere.
Processed on your device: your files are never uploaded. How it works
Network activity in this tab
What this page has requested since you opened the site in this tab. An upload is any request that sends data: POST, PUT, PATCH or a request with a body.
No uploads: nothing has been sent from this page.
No network requests yet.
To see every request, open your browser's developer tools (Network tab).
How to use the Audio Converter
- Choose the output format and its bitrate or bit depth.
- Optionally change sample rate or channels, normalize, or set a trim start and end that applies to every file.
- Drop audio or video files (as many as you like): each one is converted on your device with a progress bar.
- Download files one by one, or all of them as a ZIP.
Credits & open source
Our own code plus open-source libraries. Thank you to the people who make these projects.
- MediabunnyReads, writes and converts media files with WebCodecs (MP4, WebM, MKV, MOV, MP3, WAV, Ogg...). © Vanilagy and contributors · MPL-2.0
- @mediabunny/flac-encoderFLAC encoder (libFLAC compiled to WebAssembly, BSD-3-Clause) for Mediabunny. © Vanilagy; libFLAC by Xiph.Org Foundation · MPL-2.0
- lamejsMP3 encoder (port of LAME), loaded as a separate unmodified chunk. © LAME project; JavaScript port by Alex Zhukov; ESM fork by Breezystack · LGPL-3.0
- fflateFast ZIP compression for batch downloads. © Arjun Barrett · MIT
Web platform APIs used: Web Audio API, File API.
Full license texts: third-party notices · all credits
Frequently asked questions
Which format should I pick?
MP3 for maximum compatibility, M4A for Apple devices, Opus for the best quality at small sizes, FLAC to keep lossless quality in less space, and WAV for editing.
Can I extract the audio from a video?
Yes. Drop an MP4, WebM or MOV file and the sound track is converted to the format you choose.
Does converting MP3 to FLAC or WAV improve quality?
No. Lossless formats keep exactly what goes in; they cannot restore detail an MP3 has already removed.