MLS (Multiple Listing Service)

The MLS is a private database that real estate agents share to list homes for sale and search for properties for their clients. When a listing agent puts a home on the market, they enter it into the MLS. Buyer's agents then search the MLS to find suitable homes for their clients.

What you see on Zillow, Realtor.com, and other home search sites is largely pulled from MLS data, though sometimes delayed or incomplete. The MLS is the source of truth.

Not everyone can access the MLS directly. It's generally available to licensed real estate professionals through their local real estate board membership.

For sellers, listing on the MLS gives your home maximum exposure to agents and buyers who are actively searching. A listing that's not on the MLS (sometimes called "off market") misses the majority of potential buyers.

For buyers, working with an agent gives you access to MLS listings in real time, often before they appear on third-party sites. Agents can also set up automated alerts so you're notified immediately when a new listing matches your criteria.

A homeowner lists their home with an agent. The agent enters the property into the North Alabama MLS. Within hours, buyer's agents across the region can see the listing and share it with clients who are searching for that type of home. Syndication to Zillow and Realtor.com follows shortly after.

"Zillow is the MLS."

Zillow and similar sites pull data from the MLS, but they're not the same thing. The MLS is the primary source: agent-only, real-time, and comprehensive. Zillow is a consumer-facing tool that aggregates data but may lag behind the MLS and sometimes contains errors or incomplete information.