I couldn't find a nice worldcup bracket visualizer out there so ended up building one. It's nicer than the ones I saw out there. There is no login, no ads, runs client side, uses localStorage and all the state is encoded in the URL itself and you can share it.

The calendar feature is nice. I wanted to build my own schedule for the games I was interested in. There is full calendar that you can subscribe to as well, that gets updated as the fixtures get decided. I also wanted to be able to interactively change things and visualize the whole knockout stage.

All the state is in the URL fragment. It's a handrolled compact byte format. About 203 bytes, ~217 characters. The URL has the full snapshot so the link you share always renders the same brackets. It's versioned so you can change the format not break links out there.

At this point it does everything I wanted it to do for me. Might be some real howlers in there. Let me know if you spot one.