This page shows how different Go libraries generate a unique id:

github.com/rs/xid	db0ibg1mgkj2ej5sumug
github.com/segmentio/ksuid	3KBtu7OPnRSxzm99NOVladl4MWJ
github.com/oklog/ulid	01M417PXH4RSVXJP6YHTBD2SJ0
github.com/sony/sonyflake	8e1ff4303000001
github.com/chilts/sid	1791043008036373049-4550170974109407443
github.com/satori/go.uuid	414075c1-854a-41ca-9a4e-bb4e7a0b0222

Learn more about those libraries.