Audio Converter Online Free
Convert audio files between MP3, WAV, FLAC, AAC, OGG, and M4A. Drag in a video file to extract just the audio track. Everything runs in your browser — your files stay on your device.
Audio files come in formats that don't always work on every device or platform. A FLAC album won't play on most car stereos. An MP4 video has an audio track you can't easily use on its own. A WAV recording from a podcast session is ten times larger than it needs to be for publishing. Choosing the right format and quality setting makes a practical difference.
This free online audio converter handles the most common audio format changes directly in your browser. It converts between MP3, OGG, WAV, AAC, FLAC, and M4A, and extracts audio from video files like MP4, MOV, MKV, and AVI. All processing uses FFmpeg compiled to WebAssembly — your files never leave your device, and no software installation is needed.
How to Convert Audio Online
- 1Upload your audio or video file by dragging it into the box or clicking to browse.
- 2Pick the output format from the grid: MP3, OGG, WAV, AAC, FLAC, or M4A.
- 3For MP3, select your preferred quality (128 kbps, 192 kbps, 320 kbps, or VBR).
- 4Click Convert. The first time, the browser downloads the FFmpeg engine (about 30MB) once.
- 5When conversion finishes, preview the audio and click Download.
- 6Add more files to batch convert with the same settings.
When to Use This Tool
- Extracting an MP3 soundtrack from an MP4 video or YouTube download
- Converting FLAC albums to MP3 for devices that don't support lossless audio
- Preparing audio for podcast editing software that requires a specific format
- Converting WAV files to AAC for smaller iPhone-compatible files
- Batch converting a music library to a single format
- Saving a voice memo from MOV format to plain MP3
Real World Examples
Extracting audio from a recorded meeting
A project manager records a 45-minute Zoom call as an MP4. She only needs the audio for transcription. Uploading the MP4 and selecting MP3 output extracts the audio track in about 2 minutes, dropping the file from 900MB to 65MB.
Converting a FLAC library for a portable player
An audiophile has 300 FLAC albums totaling 80GB. His older car stereo only reads MP3. Batch converting at 320 kbps preserves near-lossless quality while reducing storage to around 25GB.
Preparing podcast audio for publishing
A podcaster records in WAV for maximum quality during editing. Before publishing, he converts to MP3 at 192 kbps VBR. The resulting file is about 10x smaller than the original WAV with no audible difference for listeners.
Benefits of This Audio Converter
- Extracts audio from any video format — MP4, MOV, MKV, AVI, WebM and more
- Supports 6 output formats: MP3, OGG, WAV, AAC, FLAC, M4A
- Adjustable quality for MP3 (128, 192, 320 kbps, VBR) and OGG (0 to 10 scale)
- Batch mode: queue multiple files, same settings applied to all
- Audio preview player after conversion — listen before downloading
- Files never leave your device. All processing runs in the browser.
- Free with no account, watermark, or file count limit
Audio Format Comparison
| Format | Type | Best for |
|---|---|---|
| MP3 | Lossy | Universal compatibility — works on all devices and platforms |
| OGG | Lossy | Web and open-source projects; slightly better quality than MP3 at same bitrate |
| WAV | Lossless | Audio editing and production — no quality loss, large file size |
| AAC | Lossy | Apple devices and streaming; better quality than MP3 at same bitrate |
| FLAC | Lossless | Archiving music with perfect quality and reasonable file sizes |
| M4A | Lossy | iTunes and Apple ecosystem; same as AAC in an M4A container |
Tips for Best Results
- Use VBR MP3 for music — it gives better quality than a fixed 192 kbps at a similar file size.
- Choose FLAC when archiving original recordings you want to keep without any quality loss.
- Convert WAV to AAC for Apple devices. AAC at 192 kbps sounds better than MP3 at the same bitrate.
- For voice recordings and podcasts, 128 kbps MP3 is enough. Higher bitrates don't help speech audio much.
- Converting from one lossy format to another (like OGG to MP3) always reduces quality. Start from lossless source files when you can.
- Large video files (over 200MB) may take a few minutes in the browser. Keep the tab active during conversion.
Frequently Asked Questions
Can I extract MP3 audio from an MP4 video?
Yes. Upload the MP4 file, select MP3 as the output format, and click Convert. The converter strips the audio track and discards the video. This works with any video format — MOV, MKV, AVI, WebM, and more.
Is this audio converter free?
It is completely free. There are no accounts, subscription fees, or limits on how many files you convert.
Why does the first conversion take longer?
The first time you use the converter, your browser downloads FFmpeg compiled to WebAssembly (about 30MB). After that, the browser caches it and subsequent conversions start immediately.
Are my audio files uploaded to a server?
No. All conversion happens inside your browser using WebAssembly. Your files never leave your device.
Which format gives the smallest file size?
OGG and AAC typically produce smaller files than MP3 at the same audio quality. FLAC and WAV are lossless and much larger — use them only when you need perfect quality for archiving or editing.
Can I convert multiple files at once?
Yes. Upload as many files as you need. They convert one by one with the same settings. When all are done, you can download them individually or all at once.
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Conclusion
Whether you need to pull an MP3 from a recorded video, compress a FLAC library to MP3 for a portable player, or batch convert audio files for a project, this free online audio converter handles it in the browser without any software installation. Choose your format, set the quality, and download. Use the tool above to start converting your audio files now.