> you'll match the last few and first few letters just as fast in your head Definitely true, in fact I tend to prefer hex for this purpose. But one minor note

> you'll match the last few and first few letters just as fast in your head Definitely true, in fact I tend to prefer hex for this purpose. But one minor note - assuming the whole thing is cryptographic-strength random, there's no need to compare first and last, just do first only or last only (last is usually preferred for UUIDs due to them sometimes containing a timestamp at the start), the odds of an accidental match is the same and the visual processing time of switching from one end to the other is lower.