Everyone talks about HTTP/3 like it’s a free speed upgrade you flip on and forget. It mostly is — but “mostly” is doing a lot of work in that sentence. HTTP/3 is now used for roughly 35% of all web requests globally [1], so this isn’t a research toy anymore. The thing is, almost no one explains why it’s faster, where it actually loses to HTTP/2, and — the question nobody asks — whether your particular site even benefits. Let me walk through it the way I’d explain it to a friend over chai.