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

github.com/rs/xid	dbe06s9mgkj5nt1smdig
github.com/segmentio/ksuid	3L7Sd9WSUM0ACSeJIY4YOKVSyO0
github.com/oklog/ulid	01M5NPTWEG756BBDB7JQCEAPYX
github.com/sony/sonyflake	8ec7ddc2e000001
github.com/chilts/sid	1792803697105287638-2167493139500220470
github.com/satori/go.uuid	e38ab1bd-016a-4be0-a9ce-9d256f05bd80

Learn more about those libraries.