IDs and Test Data
Last updated: 27 September 2026
Test data should be recognisable as test data. A random-looking identifier is useful for avoiding accidental collisions in a demo; it is not automatically an account, a valid document number, or a safe password.
Choose the right kind of value
UUIDs and ULIDs are identifiers with different shapes and ordering properties. Pick the format your application expects rather than converting every ID just because a generator can. For sample email and web addresses, use reserved examples such as user@example.com and example.com.
Do not confuse shape with validity
A string that matches a format may still fail business rules or uniqueness checks. Test both valid-looking and deliberately invalid inputs. Keep generated sample data separate from production records so it is not mistaken for a real person.
Related tools
- ULID Generator — Generate sortable ULIDs, single or in bulk.
- UUID Generator — Generate v4 UUIDs, single or in bulk.