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Real Estate Sites Decoded: How Listings Reach Zillow, Realtor.com & More
How Real Estate Sites Pull from the MLS — and What That Means for You
Real Estate Navigator
December 04, 2025
In partnership with
After the Leftovers: How Zillow, Realtor.com, and Redfin Really Get Their Listings
Hope you had a relaxing Thanksgiving and maybe a few good sandwiches from the leftovers. Now that we’re back, let’s talk about something that quietly shapes how we all browse homes online: how big real estate sites actually get their listings—and what that means for buyers, sellers, and curious homeowners.
The Backbone: The MLS (Multiple Listing Service)
Behind every home you see online sits a database called the Multiple Listing Service, or MLS.
Each region has its own MLS, where licensed agents enter property details: price, photos, features, and status updates.
Agents use it to share listings with one another, so homes get maximum exposure.
Consumers don’t have direct access to the MLS. What you see on Zillow or Redfin is usually a syndicated copy of that data.
Think of the MLS as the master recipe. Zillow and friends are the cookbooks built from it.
The bridge between MLS databases and public websites is called Internet Data Exchange (IDX).
IDX allows MLS data to be shared on broker and consumer websites.
Big portals like Zillow, Realtor.com, and Redfin use syndication feeds to pull this information.
The data is refreshed at different intervals, which means not every site updates at the same speed.
Bottom line: the MLS is the source of truth, while IDX is the delivery system that gets those homes onto your screen.
How Each Site Gets Its Listings
Platform | How It Gets Listings | What You Should Know |
|---|---|---|
Zillow | Pulls data through MLS syndication and broker feeds. | Great reach, but updates can lag. A home may show as “active” when it’s already under contract. |
Receives direct MLS feeds from hundreds of MLSs nationwide. | Often the fastest and most accurate for real-time updates. | |
Redfin | Uses its own MLS feeds or partnerships with local MLSs. | Clean design and solid data, though coverage varies by region. |
No single portal covers everything. Each has strengths, quirks, and timing gaps.
What Buyers Should Know
Cross-check listings. Because each site updates at a different pace, check more than one platform for the full picture.
Confirm status before you fall in love. A listing marked “active” may already be under contract. Ask your agent to verify.
Remember private or “coming soon” listings. Some homes are listed in MLS but not syndicated publicly yet, so they won’t show up online right away.
What Sellers Should Know
Ask about syndication. Your agent can confirm where your listing will appear and how quickly.
Expect a short delay. Even after your home goes live in the MLS, it may take a day or two to appear everywhere.
Understand your options. Some sellers choose not to syndicate to every platform, especially for privacy or strategy reasons.
The Big Picture
Real estate portals are amazing for browsing and research. They make home shopping easier than ever. But the MLS remains the original and most accurate source for listings and updates.
Use Zillow, Realtor.com, and Redfin as powerful tools—but not the final authority.
Bottom Line:
If you’re serious about buying or selling, use the national sites as your preview, not your proof. Always confirm details through your agent or the local MLS data they access directly.
Until next week!
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