How Do Zillow & Trulia Get Listings, and Are They Accurate?

There’s been a lot of noise in the news lately about real estate brokers and/or customers complaining that the listings on Zillow and Trulia are inaccurate, not updated, or just plain wrong compared to the local Realtors Multiple Listing Service database (MLS). As a weekly personal user of these sites, I can tell you that I’ve hardly found a single issue with the accuracy of the data on those sites. In fact, I’ve found gems of information that sometimes are not on the MLS! Let’s take a look at how the listings of properties for sale work and what you need to do to make sure the information you find is accurate.

First, let's discuss how the MLS works. The MLS has been around for decades, although it has only been online for the past decade or so. Realtors who are members of the local association of Realtors work with sellers to get signed listing agreements, which allows them to sell their properties and then post that information onto the MLS so that all MLS members can see the properties for sale. The MLS has the most accurate, up to date, and 100% valid data as long as the real estate agents update the information when the status of a property changes. And the MLS was the only source of listing data before Internet usage was common, so real estate buyers had to rely solely on their real estate sales agent for information about available properties. But those days of dependence are gone!

Now that Internet usage is widespread, websites are springing up to place the property listing data — once exclusive to the MLS — online for all to use. As you are probably aware, Internet listings have become an incredible place to find great data and information to help buyers and sellers review, scan, search, and analyze listings and sales data, helping to make them more educated consumers. And that makes a better real estate market for all parties interested in buying or selling real estate for themselves. Some real estate agents were hesitant at first, and some still are, as per this Financial Times story, but the truth is that more data is better for consumers, even if it isn’t always better for sales professionals.

Anyone, for free, can go to Zillow, Trulia, Ziprealty, Redfin, etc. and search property listings to see what is available for sale, along with prices, pictures, reviews of agents and reviews of the properties. And those sites have more information than is available even on the MLS! Now you might wonder where they get all the information. Well, they get it from companies called aggregators, which in turn get their information from agreements with the MLS providers, brokerage houses, services that provide property default and foreclosure notices, and lots of other places. With all these data streams coming into the aggregator from different software programs, there will inevitably be inaccurate data or missing information from time to time, although I’ve never seen incorrect data myself. And most online sites are updated at least once per day, so it’s likely you will see every listing when you are searching.

As an added bonus, these sites have foreclosure data, which the MLS will not, and they also have listings from for sale by owners (FSBO), and even could have properties listed by an MLS service provider that is from out of the general area. Any and all of that data can give a buyer or a seller additional insight into the market and pricing. And that’s better for consumers!

To make sure the information you see is accurate, though, you will need to confirm the data with your local real estate professional. But you have to work with a Realtor anyhow to offer upon any MLS listed properties, so start interviewing agents to select one that will do a great job for you. And once you get going, use all the tools available in your search, online and off-line! That’s going to get you your best outcome when you are ready to sell or take the property-buying plunge.

Full disclosure: I am one of the Zillow Featured Bloggers – but I believe once you search the online sites you will agree with my findings above.