Audio Converter
FLAC files from your music library, a WAV recording, an M4A from your phone: the table below shows at a glance which audio format wandlio converts into which. Rows are the format you have, columns the one you want.
Everything runs in your browser: open formats are handled by ffmpeg.wasm, a browser build of the FFmpeg tool, while AAC and M4A use your browser’s built-in codecs. Your file stays on your device.
Every audio conversion at a glance
“Browser” means the conversion runs in your browser with no upload – your file stays on your device. “Server” means the file is sent over an encrypted connection (HTTPS) to our servers in Germany and deleted right after conversion.
| From / To | MP3 | WAV | FLAC | OGG | M4A | AAC |
|---|---|---|---|---|---|---|
| MP3 | – | MP3 to WAV Browser | MP3 to FLAC Browser | MP3 to OGG Browser | MP3 to M4A Browser | MP3 to AAC Browser |
| WAV | WAV to MP3 Browser | – | WAV to FLAC Browser | WAV to OGG Browser | WAV to M4A Browser | WAV to AAC Browser |
| FLAC | FLAC to MP3 Browser | FLAC to WAV Browser | – | FLAC to OGG Browser | FLAC to M4A Browser | – |
| OGG | OGG to MP3 Browser | OGG to WAV Browser | OGG to FLAC Browser | – | OGG to M4A Browser | – |
| M4A | M4A to MP3 Browser | M4A to WAV Browser | M4A to FLAC Browser | M4A to OGG Browser | – | – |
| AAC | AAC to MP3 Browser | AAC to WAV Browser | AAC to FLAC Browser | AAC to OGG Browser | – | – |
| AIFF | AIFF to MP3 Browser | – | – | – | – | – |
| MP4 (video) | MP4 to MP3 Browser | MP4 to WAV Browser | – | – | – | – |
The last row extracts the soundtrack from a video; MP4 to MP3 also accepts MOV, WebM, MKV and AVI files.
Which audio format for which job?
The key question: do you want to save space or keep every detail?
| If you want to … | Use … | Why |
|---|---|---|
| play music on almost any device | MP3 | supported by a huge range of devices and apps; wandlio encodes at 192 kbps |
| edit or cut a recording | WAV or FLAC | lossless – recompressing lossy audio would compound artefacts |
| archive music without loss in less space | FLAC | for 16- and 24-bit sources, the decoded audio is identical to the original |
| listen on Apple devices | M4A | an audio-only MP4 file; wandlio uses AAC |
| use an open, royalty-free format | OGG (Vorbis) or FLAC | both are free of licensing requirements |
| improve the quality of an MP3 | not possible | Detail lost during compression doesn't come back in FLAC or WAV – the file just gets bigger. |
Audio formats explained
- MP3
- Lossy (MPEG-1 Audio Layer III). Its patents have expired, so the format is free to use. wandlio writes MP3 at a constant 192 kbps.
- AAC
- A lossy codec found in MP4 and M4A files or as a raw AAC stream (ADTS). wandlio has your browser’s built-in encoder create AAC at 128 kbps; Firefox doesn’t have one.
- M4A
- An MP4 file that only contains audio – for example AAC or the lossless ALAC (Apple Lossless). wandlio creates M4A with AAC at 128 kbps.
- WAV
- A Microsoft and IBM format that almost always holds uncompressed linear PCM: lossless, but large. wandlio writes 16-bit WAV, or 24-bit when the source is lossless at a higher resolution.
- FLAC
- Free Lossless Audio Codec: lossless compression that MDN puts at up to 40–50 % smaller, with no licensing requirements.
- OGG
- The Xiph.org Foundation's container for codecs such as Vorbis, Opus or FLAC. wandlio writes OGG with Vorbis at 128 kbps.
- AIFF
- An audio format developed by Apple; the common variant stores uncompressed PCM, much like WAV.
How in-browser conversion works
For MP3, OGG, FLAC and WAV, your browser fetches ffmpeg.wasm from wandlio.de the first time; AAC and M4A use its built-in codecs. Either way, your own device does the work and the file is never uploaded.
Settings are fixed: MP3 at 192 kbps, AAC and M4A at 128 kbps, OGG with Vorbis at 128 kbps. FLAC and WAV are lossless, and embedded cover art is carried over to MP3 and M4A where possible.
Expect audiobooks and long live recordings to need some patience – the encoder works through them one thread at a time.
Audio guides
More on codecs, bitrates and the technology behind in-browser conversion:
Related category
- Convert video
Convert videos between MP4, MOV, MKV and WebM, or save a video's soundtrack as MP3.