> The Odds a UUID Ever Repeats

A version-4 UUID has 122 genuinely random bits (the other 6 are fixed, marking it as version 4). Birthday-paradox math says you'd need to generate roughly 2.71 quintillion of them before the odds of any two colliding crossed 50%. Every UUID this site has ever generated, and every one it ever will, is functionally guaranteed unique - not because the math forbids a collision, but because the universe will have other problems long before that number of UUIDs gets generated by anyone.