Search the real thing.

1 · What it actually is

Heartland MLS is the database. The portals are photocopies of it.

Heartland MLS is the multiple listing service for the Kansas City metro — the shared, broker-run database where a listing is entered when it comes to market, amended when the price moves, and marked pending when somebody signs. Every agent on both sides of the state line works in it. When your agent says a house “just came on,” this is the thing it came on to.

The national portals do not have their own listings. They receive a feed from services like this one, on their own schedule, and then they garnish it — an estimate, a walk score, a “heat index.” The estimate is the product; the listing is the raw material. Which means two things worth knowing before you fall in love with a house on your phone: what you are looking at is a copy, and the copy is late.

• The status is the thing that goes stale first.

  A house that went under contract on Thursday can still be sitting there, bright and available, on a portal on Saturday morning. In a market where the good ones move in a weekend, that is the difference between an offer and a disappointment.

• The estimate is a model, not a price.

  It is a national algorithm guessing at a metro it has never driven. It does not know that the state line runs down the middle of a street, that one side pays an earnings tax and the other does not, or that the county assessor reassessed last spring.

• Days on market can be laundered.

  Withdraw a listing and relist it and the counter can go back to zero. The MLS keeps the history. A portal often shows you the fresh number and not the four months behind it — and that number is your negotiating position.