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

github.com/rs/xid	daj3nbhmgkjd43e20s00
github.com/segmentio/ksuid	3JGEku1MSOlDtmILe2fT3SGET56
github.com/oklog/ulid	01M2CNJ8W3XVBYECMTWRXVEZA4
github.com/sony/sonyflake	8d77bd459000001
github.com/chilts/sid	1789279150979967437-6754208516382287708
github.com/satori/go.uuid	837555c8-78a1-4972-a6e8-f3f45865acd9

Learn more about those libraries.