Random token generator

A token is a secret that only a machine has to read, so it can be long and ugly. What matters is that it comes from a cryptographic source and carries enough entropy — 128 bits is the usual target, which is 32 hex characters or 22 base62 ones.

The formats exist for different reasons. Hex is universally safe and wastes space — four bits per character. Base32 survives being read aloud or typed on a phone keypad and is what TOTP secrets use. Base58 is hex’s alphabet minus the characters people confuse, which is why Bitcoin addresses use it. Base62 is the densest that stays alphanumeric, so it survives a URL without escaping. A UUID v4 carries 122 random bits, which is plenty, but say what you mean: a UUID identifies, a token authenticates, and using one as the other has caused real breaches.