Users would visit these sites, search for their favorite artist or viral trend, and download the .3gp file directly to their phone's memory card.

Sites like "3gpking" were part of a massive "YouTube-to-mobile" ecosystem. Before YouTube had an official offline "Download" button or a robust mobile app, users relied on third-party converters to watch content on the go.

The "King" offers dramatically smaller files, but you lose subtitles, high frame rates, and surround sound.

Converting a YouTube video to 3GP typically follows one of three approaches. Each has its own pros and cons.