A real address is coherent: the street exists in that city, the postcode serves that street, the city sits in that region. Those relationships are what anything downstream relies on when it treats an address as more than free text.
A fake-data tool can either respect those relationships or ignore them. That choice is invisible until something in your system actually reads the parts as related.
How Faker builds an address
Faker’s location module exposes city(), street(), zipCode(), state() and streetAddress() as independent methods. Each draws at random from that locale’s list — a random city name here, a random street name there, a postcode from a format pattern. There is no link between them: the street is not a street in that city, and the postcode is not the postcode for that street. Each piece is individually plausible; together they describe a place that does not exist.
For many uses that is completely fine — if nothing you build ever compares the city to the postcode, the incoherence never surfaces. But it is there.
How Real Fake Data builds an address
Addresses here are anchored to real reference data: actual cities, real street names that belong to those cities, and the postal-code ranges that genuinely serve them. Pick a city and the street and postcode you get back are ones that plausibly go with it. The record is internally consistent, so it behaves like real input all the way through.
The value is still entirely synthetic — no real resident, no real household — but the geography is real, which is what makes the record trustworthy in tests that treat the fields as connected.
When the difference shows up
A postcode-to-city lookup that should resolve. A shipping-cost estimate keyed on region. A map pin that should land in the right place. A validation rule that cross-checks postcode against city. Against independently-drawn parts, each of these either fails or silently produces nonsense; against anchored data, they behave exactly as they would in production.
Try it
Generate an address in the Playground and see the parts hang together — a real street in a real city with a matching postcode. No key required.
To be precise about Faker
Faker’s independent address parts are a deliberate, documented design — its methods are meant to be composed freely, and for placeholder data that is a feature, not a fault. The distinction is only that Faker does not promise a coherent real-world location, and Real Fake Data does.