[gobengo]

NanoIDs are shorter than UUIDs because they have a bigger alphabet. That's probably why.

It's not very important for putting IDs in URL paths. But it can matter when using them in DNS subdomains because often there are surprisingly short max character lengths for domain names in e.g. LetsEncrypt SSL certs (iirc 63 characters)

[wereHamster]

The 63 character limit is in the DNS spec, not invented by Let's Encrypt.

See https://stackoverflow.com/questions/32290167/what-is-the-max... for one explanation.