A free online MP3 converter and audio converter: switch between MP3, WAV, FLAC, OGG, M4A, AAC, and Opus in your browser. No caps, no account.
The audio converter — an online MP3 converter and much more — moves files between MP3, WAV, FLAC, OGG, M4A, AAC, and Opus. MP3, WAV, and Opus use encoders your browser already has, so they're immediate; the rest are handled by a conversion engine that downloads to your browser once on first use and is cached from then on. Either way, your file itself is never uploaded — the engine comes to you rather than the other way round.
Convert when something won't play, when a file is too big to send, or when you need a lossless copy for editing. The one rule worth internalising is direction: going lossless to lossy costs you a little once, and going lossy to lossy stacks the damage — so keep a WAV or FLAC master and export to MP3 last. How to convert audio formats explains it properly, and the best formats for editing covers which to use when.
You can read almost anything your browser plays — MP3, WAV, FLAC, M4A, and AAC work in every modern browser, and OGG/Opus additionally work in Chrome and Firefox — and convert to any of seven formats: MP3, WAV, FLAC, OGG (Vorbis), M4A (AAC), raw AAC, and Opus. WAV and FLAC are lossless (WAV uncompressed, FLAC compressed but bit-perfect); the rest are compressed formats where you pick the bitrate.
Those encoders aren't built into browsers, so the first time you pick one of them, the tool downloads our audio engine — a WebAssembly build of FFmpeg, about 20 MB, fetched once from our own domain and then cached, so it's instant on later visits. It's a download to your device, like any page asset; your file still never leaves your browser. MP3, WAV, and Opus don't need it at all — they use encoders that ship with the site and convert immediately.
Yes, with two format caveats that are Safari limitations rather than ours. Safari cannot decode OGG or Opus files at all, so those inputs need Chrome or Firefox — MP3, WAV, FLAC, M4A, and AAC inputs all work fine in Safari. And because native Opus encoding relies on a browser capability Safari doesn't ship, the Opus output option is hidden there — all six other output formats work. The tool only ever shows you options that actually work in your browser.
It depends on the target. Converting to WAV or FLAC is lossless — no quality is lost in the conversion itself. Converting to MP3, OGG, M4A, AAC, or Opus re-encodes the audio at your chosen bitrate; higher bitrates preserve more detail. Bear in mind that converting an already-lossy file (say an MP3) to another lossy format can't recover detail that was lost the first time, and stacking lossy encodings compounds the loss — so convert from the highest-quality source you have.
Nothing is uploaded — decoding and encoding run entirely in your browser, and you can prove it: convert once, disconnect from the internet, and convert again. Files are capped at 100 MB (hours of compressed audio) with a clear message rather than a crashed tab, since the decoded audio lives in your browser's memory. The MP3 encoder (LAME) and the FFmpeg audio engine are LGPL-licensed — the project's two documented license exceptions, both listed with full text on the Licenses page — and each loads only when a format that needs it is used.
Yes — it's a free online MP3 converter with no account, no watermark, and no file-size cap set by a server. Convert to MP3 from WAV, FLAC, M4A, AAC, OGG, or Opus (and convert MP3 out to any of those too), choosing the bitrate yourself. The MP3 encoder runs in your browser, so conversions to MP3 are instant and your file never leaves your device. There are also dedicated single-pair pages like M4A to MP3 and WAV to MP3 if that's all you need.