Audio file converter

No. Everything happens in your browser, and this site has no way to receive your file.

Yes. Open this page, then disconnect from the internet. With the connection off, you can still choose a file and save the result.

For the first few seconds after the page opens, it is still fetching the parts it needs, so wait a moment before disconnecting. Reloading the page needs the connection again.

Note that some of the other tools on this site fetch extra parts after reading your file — for example, the character tables needed to show a PDF that does not embed its fonts. If you have a data-saving setting turned on, nothing is fetched ahead of time either, so a connection is needed then too.

Five, and you can choose the quality or bit depth too.

• MP3 — plays on anything, including older car stereos.
• M4A (AAC) — a good balance of quality and size; plays on iPhone as-is.
• Opus — best quality for the size, but fewer devices support it.
• FLAC — lossless compression, smaller than WAV. 16-bit or 24-bit.
• WAV — uncompressed, for handing to an editor. 16-bit or 24-bit.

MP3, WAV, M4A (AAC and ALAC), FLAC, Ogg (Vorbis and Opus), WebM, AIFF — almost anything your browser can play. WMA cannot be opened, because Chrome cannot play it.

No. MP3, AAC and Opus work by throwing away sound you are unlikely to hear. What was thrown away is not in the file any more, so a lossless format cannot bring it back — it only makes the file bigger. Choose lossless when you want no further loss in later editing.

From WAV, FLAC, ALAC or AIFF to WAV or FLAC. None of those throw anything away, so the audio survives the trip unchanged. The exception is saving a 24-bit source as 16-bit, which does change it slightly.

Normally no — the file is written at whatever rate it came in at. The one exception is Opus, which can only store 48kHz, so choosing Opus resamples to 48kHz (the result screen says so).

For a 3 minute track: about 2 seconds for WAV, about 5 for FLAC or Opus. MP3 takes around 10 seconds, because browsers cannot write MP3 and the tool builds it itself.

That is what the audio extractor is for. It takes the audio out of a video without rebuilding it.

Every feature, as many times as you like. There is no daily cap, nothing changes if you sign up, and you will never be asked to pay later.

There is a limit on file size, but it comes from what a browser can handle at once. The work runs on your own device, so there is nothing for us to meter. The exact figures are in the other answers on this page.

Yes. Please keep the following in mind.

• Long audio can stop partway. About an hour is the rough limit. A computer has more room.
• Keep this page open while it works. Switching to another app stops it.
• Some formats, such as Opus, cannot be made on an iPhone. Choose another format if it fails.
• Saved files go to the Files app. To put them in Photos, use "Share" next to the download button.