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Audio converter (MP3, WAV, AAC)

Convert audio to MP3, WAV or AAC and pick the bitrate. Everything runs in your browser, your file never leaves your device.

How Audio converter works

Audio converter transcodes any audio file to MP3, WAV or AAC entirely inside your browser, with no server involved. Drop a voice memo, a studio recording, a podcast export or any common audio file and receive the converted result as a local download. The engine is ffmpeg compiled to WebAssembly, which handles format detection and re-encoding on your own device.

MP3 (encoded with libmp3lame) is the most compatible choice for sharing and streaming. WAV (pcm_s16le) is uncompressed and lossless, the right pick when you need to preserve full quality for further editing. AAC delivers better quality than MP3 at the same bitrate and is the native format for Apple devices and modern streaming platforms. Conversion speed depends on file size and bitrate; progress is shown throughout.

Written by Bastien Sulyan

How to use Audio converter, step by step

  1. Drop your audio file onto the upload area (MP3, WAV, AAC, FLAC, OGG and most common formats are accepted).
  2. Select the output format: MP3 for broad compatibility, WAV for lossless editing, AAC for Apple or streaming platforms.
  3. Click 'Convert' and monitor progress as ffmpeg WebAssembly processes the file on your device.
  4. Download the converted file directly to your device when complete.

Common use cases

  • Podcast export: convert a WAV recording from your DAW to MP3 for upload to podcast directories.
  • Apple device compatibility: convert an OGG or FLAC file to AAC so it plays natively on iPhone or iPad.
  • Archival: convert compressed MP3 files to WAV before editing them further in audio software to avoid generation loss.
  • Voice memo sharing: convert an M4A voice memo from an iPhone to MP3 so it plays on all devices.

Frequently asked questions

Which input formats does the audio converter accept?

ffmpeg compiled to WebAssembly handles most common audio containers, including MP3, WAV, AAC, M4A, FLAC, OGG and OPUS. The exact list depends on which codecs are compiled into the WebAssembly build, but the formats you encounter in everyday use are all supported.

Is there a quality difference between MP3, WAV and AAC output?

WAV (pcm_s16le) is uncompressed and lossless: no quality is lost compared to the source audio at the same sample rate. MP3 and AAC are both lossy compressed formats. AAC generally produces better quality than MP3 at the same bitrate, so a 128 kbps AAC sounds closer to the original than a 128 kbps MP3. If quality is critical, convert to WAV.

Why does converting a large FLAC file take several minutes?

ffmpeg runs inside the browser via WebAssembly, which is slower than native ffmpeg because it lacks direct hardware access and runs in a sandboxed environment. Conversion time scales with file duration and bitrate. The progress bar shows how far along the conversion is so you know it is still working.

Does the audio converter send my file to a server?

No. ffmpeg is compiled to WebAssembly and executes entirely in your browser tab. Your audio file is read into local memory, re-encoded there (libmp3lame for MP3, pcm_s16le for WAV, or the native AAC encoder), and the result is offered as a download from your device. Nothing reaches Sunasty's servers.

Can I convert a video file's audio track with this tool?

This tool is designed for audio files. To extract the audio track from a video file like MP4 or MKV, use the dedicated extract-audio tool instead, which is optimized for that task.

Does converting MP3 to WAV restore lost quality?

No. WAV is uncompressed, but the information already removed during the original MP3 encoding cannot be recovered. Converting MP3 to WAV gives you a lossless container around a lossy source. It is useful if you need to edit the file in software that requires WAV input, but it does not undo compression artefacts.

Can I convert an audio file on my phone, and will the output have a watermark?

Yes, and no watermark is ever added. A typical voice memo or song converts quickly even on mobile Chrome or Safari, since audio files are far lighter on memory than video. The one caveat is the ffmpeg.wasm engine's first-use download, which uses mobile data unless you are on Wi-Fi.