Audio Converter

Which format should I choose?

MP3 plays everywhere and is a good default (192 kbps sounds very close to the original for most music). M4A (AAC) is a little more efficient at the same size and is what Apple devices use. OGG Vorbis and Opus are open formats; Opus is the best choice for speech and low bitrates. WAV and FLAC are lossless: FLAC is about half the size of WAV and keeps the tags. Converting from a lossy file (such as MP3) to a lossless one does not bring back detail that was already thrown away.

MP3 and WAV are made straight away in your browser. OGG, M4A, FLAC and Opus (and MP3/WAV when you tick the engine option, or when your browser cannot read the file itself) use ffmpeg compiled to WebAssembly. That engine is about 31 MB; it is downloaded only when you press Convert, checked for integrity, and kept by your browser so next time it starts at once. To cut a clip first, use the MP3 cutter. The engine is ffmpeg.wasm, open-source software.

Frequently asked questions

Is my audio uploaded?

No. The conversion runs on your device. The only download is the conversion engine itself, and only for the formats that need it.

Why does the first conversion to OGG or M4A take longer?

Your browser has to fetch the 31 MB engine once. The page shows the download progress separately from the conversion progress. Afterwards it is stored in your browser.

Will it keep the album art?

Tags are kept when the engine is used; embedded cover pictures are not copied.