Ever wondered where Zillow, Realtor.com, Homes.com, or Redfin get their listings? The answer isn’t a mystery — it’s the Multiple Listing Service, better known as the MLS. 

While most buyers and sellers scroll through portals and apps without giving it much thought, nearly all those listings originate in one place: the MLS.

I was reminded of just how central this system is when I was in Toronto, where industry leaders were gathered at the Council of Multiple Listing Services Open House conference and International MLS Forum. The conversations there underscored something we sometimes take for granted. The MLS is more than just a database. It’s the foundation of transparency, cooperation, and trust in real estate.

What is the MLS?

The MLS is a shared database of property listings created and maintained by local Realtor associations and their members. But calling it just a database undersells its role. It’s a cooperative marketplace. When a Realtor enters a new listing, it becomes visible to every other Realtor in the system who may have a buyer.

This cooperation is what makes real estate in the U.S. and Canada efficient and transparent. Instead of brokerages keeping listings to themselves, the MLS creates a level playing field. Every member has access to the same accurate, up-to-date information — and consumers benefit.

Source of truth 

Online real estate feels limitless. With a few clicks, buyers can browse thousands of homes across multiple sites. But behind the scenes, those sites are pulling from one common source: the MLS.

Through data-sharing agreements, such as the Internet Data Exchange and syndication, MLS data flows out to portals like Zillow and Realtor.com. When a new home hits the market, it’s in the MLS first — and then it’s distributed to the consumer-facing websites most people use.

Accuracy is what sets the MLS apart. Realtors are required to keep their listings current. For instance, if a home goes pending, it must be updated. If the price changes, it must be adjusted. If the property sells, it must be marked closed. This structure ensures consumers are working with the most reliable information available.

Helping price homes

For sellers, the MLS is more than just a marketing tool. It’s also the most important source of pricing data. Realtors use MLS records of active, pending, and recently sold homes, which are often called “comparables,” or “comps,” to help determine an appropriate listing price.

Because the MLS requires accurate reporting of sales data, it provides the clearest picture of what buyers are actually paying in the current market. That gives sellers confidence that their home is priced competitively — not too high to scare buyers away, and not too low to leave money on the table.

For example, imagine three nearly identical homes in your neighborhood sold last month for around $400,000. That information is recorded in the MLS the moment those homes close. When you sit down with a Realtor to list your property, they’ll pull those sales directly from the MLS to guide your pricing strategy. This ensures your home is aligned with what buyers are truly paying — not just what someone guessed on a public website.

Consumer portals often lag in updating closed sales, or they may display incomplete data. The MLS, on the other hand, is the authoritative source Realtors rely on to guide their clients through one of the biggest financial decisions they’ll ever make.

Why this matters  

For sellers, being in the MLS means your home gets maximum exposure and is priced with the most reliable market data available. Your property isn’t limited to one brokerage’s website. It is made available to every Realtor, and through syndication, to every major real estate portal buyers are likely to search.

For buyers, the MLS can help reduce frustration. Have you ever seen the perfect home on a website, only to find out it sold weeks ago? That happens because many public sites lag behind in their updates. With the MLS, Realtors can show you what’s truly available today, saving you from chasing properties that aren’t really on the market anymore.

In short, whether you’re buying or selling, the MLS ensures you — and your Realtor — are working from the same source of truth.

Toronto, global conversation 

At the International MLS Forum in Toronto, leaders from around the world compared notes on how property data is managed. In some countries, there’s no formal MLS at all. Agents rely on fragmented websites or private networks, which often results in incomplete or unreliable information.

That global perspective highlighted just how advanced our system in North America really is. Here, cooperation and standardized rules create a trusted environment for professionals and consumers alike. The MLS isn’t just a tool. It’s an infrastructure that keeps real estate transactions transparent and fair.

MLS technology

The MLS has evolved far beyond simple property searches. Today’s systems integrate tax records, neighborhood data, public records, and even virtual tours. Some are experimenting with artificial intelligence to deliver smarter insights to Realtors and their clients.

But even as the tools change, the foundation stays the same for the MLS to provide the most accurate, up-to-date listing data that fuels every other platform. Without it, the technology would have no reliable base to build on.

Looking ahead, we’ll likely see even greater connectivity between MLS systems across regions, increased transparency for consumers, and broader global collaboration. Buyers from abroad are already searching here, and U.S. and Canadian buyers are looking overseas. The MLS will continue adapting to make those connections smoother. No matter what changes, its role as the trusted hub of listing information remains essential.

The MLS isn’t something most buyers and sellers log into directly, but it powers nearly every step of their journey. It ensures the home they see online is truly for sale. It helps sellers price their home with real-time market data, and it ensures Realtors have access to the most accurate and complete information available.

That’s why industry leaders meet to talk about it, improve it, and protect it. Because behind every portal, every website, and every search, the MLS is working quietly in the background to keep the market transparent and fair.

Karene Loman is a Realtor at Soar Homes and president of the 2,500-member Spokane Realtors association. She can be reached at 509.990.2525 or at [email protected]