Audio Converter
Convert audio to MP3, WAV, AAC, FLAC, and more, up to 20 files at once
Click or drop an audio file hereChoose an audio file (up to 20 files)
About Audio Converter
Audio Converter turns audio files into another format. It writes 19 formats: MP3, WAV, AAC, FLAC, OGG Vorbis, M4A, Opus, WMA, AIFF, ALAC, AC3, M4R (iPhone ringtone), M4B (audiobook), MP2, WavPack, CAF, AU, MKA, and AMR (phone voice). For lossy targets except Opus, which is always made at 128 kbps, and AMR, fixed at 12.2 kbps, you pick the bitrate; for every target but Opus and AMR you can also change the sample rate or mix to mono or stereo. ffmpeg.wasm converts on this page; only an Opus or AMR target, or one file too large for your browser (over 750 MB on a computer or 300 MB on a phone or tablet, up to 1000 MB), sends your original file to our server, and for such a large file the page asks you first. It takes up to 20 files at once, converted one after the other with the same settings, and you save each result on its own or all of them in one ZIP. Its picker lists audio files only: for the sound of a video, use Video to Audio.
How to convert an audio file to another format
- 1Pick, drop, or paste (Ctrl+V) the audio files you want in another format, up to 20 at once.
- 2Choose the "Target format".
- 3For a lossy format, pick the "Quality"; if needed, set "Sample rate" and "Channels".
- 4Click "Convert audio" (with several files, the button gives their number) and follow the progress bar: the files are converted one after the other.
- 5Play the result, then click "Download" to save it under your file name with the new extension. With several files, each one has its own "Download" button, and "Download all" saves them in one ZIP.
Formats and limits
- Input formats
- MP3, WAV, M4A, AAC, FLAC, OGG, OGA, Opus, WMA, AC3, AIFF, AIF, AMR, MKA, WEBA, CAF, MP2, M4B, M4R, WV, AU
- Output formats
- MP3, WAV, AAC, FLAC, OGG (Vorbis), M4A, Opus, WMA, AIFF, ALAC, AC3, M4R, M4B, MP2, WV (WavPack), CAF, AU, MKA, AMR
- Quality
- 128, 192 (default), 256, or 320 kbps for MP3, AAC, M4A, M4R, M4B, OGG, WMA, AC3, and MP2, written as chosen, except for a file sent to our media service, which uses its quality level closest to that choice. Opus: 128 kbps. AMR: 12.2 kbps.
- Sample rate and channels
- Keep the original, or 48 down to 8 kHz (OGG, AC3, and MP2: 48, 44.1, or 32 kHz only); mono or stereo. Not offered for Opus or AMR, which is always 8 kHz mono.
- Files at once
- Up to 20, converted one after the other with the same settings
- Maximum file size
- 750 MB per file on a computer and 300 MB on a phone or tablet in your browser; one file over that, up to 1000 MB and 2 hours of sound, can be sent to our media service after you agree, and a larger one is refused as soon as you choose it, before anything is sent. In a batch, a file over the browser's limit is refused and the other files are kept.
- Usage limits
- Opus and AMR targets, and a file too large for your browser: our server counts each file as one conversion, per connection per hour and per day, and refuses files over its maximum size or length.
Where your file is processed
Files up to 750 MB on a computer (300 MB on a phone or tablet) are converted in your browser by ffmpeg.wasm, downloaded from unpkg.com, for every target except Opus and AMR. For Opus and AMR, and for one larger file (up to 1000 MB) after you click the button that sends it, your original file is uploaded in pieces to our media service, hosted on Railway, converted there (libopus at 128 kbps for Opus, AMR-NB at 12.2 kbps for AMR) and downloaded back by the page; the service removes your upload as soon as the conversion ends or fails, and the result once it has been downloaded, or after 15 minutes. A failed conversion sends us its cleaned message, the file extension, a size range, and your browser's name and version.
Frequently asked questions
Can I convert several files at once?
Yes, up to 20 at a time: choose, drop, or paste them together. They are converted one after the other with the same settings; a file that cannot be converted gets its own message on its line and the others are still converted. Each result has its own Download button, and "Download all" saves them in one ZIP. To join several files into one instead, use Merge Audio.
Can I change the bitrate, sample rate, or channels?
Yes. "Quality" offers 128 to 320 kbps for the lossy formats, "Sample rate" goes from 48 kHz down to 8 kHz, and "Channels" gives mono or stereo. A rate a format cannot store, such as 22.05 kHz for OGG, is refused with a sentence before encoding.
Can I make an iPhone ringtone?
Yes. Choose M4R as the target: the page reminds you that a ringtone lasts 40 seconds at most and how to install it with GarageBand, the Finder, or iTunes. Shorten a longer song first with Trim Audio.
Can it convert to AMR?
Yes. AMR, the voice format of mobile phones (8 kHz, mono, 12.2 kbit/s), is made by our media service, like Opus: your file is sent there, then deleted. The ffmpeg build that runs in the browser has no AMR encoder.
Which formats are made on your server?
Opus and AMR, for any file; and, for one file too large for your browser (over 750 MB on a computer or 300 MB on a phone or tablet, up to 1000 MB), the formats our media service writes (MP3, AAC, FLAC, OGG, M4A, Opus, WMA, AC3, AMR), after you click the button that sends it. The whole original file goes to our server, hosted on Railway, which counts conversions per connection per hour and per day and refuses files over its maximum size or length. Any other file is converted by ffmpeg.wasm without leaving the tab.
Can I convert a file larger than 750 MB?
Yes, up to 1000 MB and 2 hours of sound, one file at a time. Your browser cannot hold a larger file than 750 MB (300 MB on a phone or tablet), so such a file is converted by our media service, hosted on Railway. The page says so first and uploads the file only when you click its button; the service deletes it as soon as the conversion ends. The 2-hour limit mostly concerns WAV, AIFF, and FLAC files: a compressed file this large lasts longer (an MP3 over about 275 MB lasts more than 2 hours), and the page refuses it before sending. ALAC, M4R, M4B, MP2, WV, CAF, AU, and MKA are written by the browser only, and WAV and AIFF are not offered for such a file, so that the result sent back stays compressed: FLAC is its lossless format.
Tips and tricks
- ✓To take the sound out of a video, use Video to Audio: it offers the same 19 formats.
- ✓ALAC writes Apple Lossless audio inside a .m4a file, the way Apple Lossless files are usually stored.