YouTube to MP3
Research tool
I use YouTube to MP3 to pull audio clips for presentations and other research materials. It records the sound of a YouTube video playing in another tab and saves it as an MP3, with no adverts and no server.
A web page cannot download a YouTube video: the browser lets a page read another site's response only when that site allows it, and YouTube does not. Converter sites get around this with a server that downloads the video for you, and many of them carry advertising. This tool has no server. You choose the video's tab, the browser shares that tab's sound with the page, and the page encodes it as an MP3 in WebAssembly. The page makes no request to any other address while it records.
Because it records what the tab plays, a recording takes as long as the clip. Silence before the first sound and after the last is left out, and recording can stop by itself after a few seconds of silence. An advert that plays in the tab is recorded too.
Sharing a tab's sound needs a Chromium-based browser on a computer, such as Chrome, Edge or Opera. Safari and Firefox share no tab sound, and the page says so. Record only what you have the right to keep.
Using the tool
Open the video in a tab, or paste its link into the page and open it from there. Select Choose the tab, pick the video's tab from the browser's list, turn on the switch to share its audio, and play the video. Select Stop and make the MP3 when the clip ends, add a title and artist if you want them in the file's tags, and save.