First of all, you need to copy the link of your YouTube video. If you are visiting the YouTube website, just directly copy the link address at the top of the browser. If you are using the YouTube mobile client, you need to click the share button below the video, find the copy link address, paste it into the input box on this site, click the "Convert" button to start extracting the video. After the conversion is successful, it will jump to a new website. Just choose the format you need to download. This site supports downloading in a variety of formats.