[matja]

Curious on the preference there, especially when characters in base64url encoding can look similar/ambiguous in some fonts.

[bajsejohannes]

The preference is purely about the amount of characters. I hope no one will ever actually read or write these URLs, but you never know...

[matja]

Ah in that case, base58 can be useful because it doesn't use characters that may be ambiguous in some fonts (doesn't use: 0/O/I/l , but does use: 1/i)