Top 20 MLS the United States

What are the largest MLSs in the United States? The table gives you the most updated list (10/10/2010), as well as links to their homepages, and their 2018 Membership numbers.

The National Association of REALTORS (NAR) is North America’s largest trade association for real estate helped set the general requirements for IDX and does a good job of coordinating the industry but the MLS space is a continually shifting landscape.

In November of 2018, a RESO official cited about 645 MLS. We’ve heard numbers as high as 1,100 when considering smaller and area specific groups.

Feel free to bookmark this page for your resource of the largest MLS. We’ll continue to update it for you, so you have a single resource.

Rank Company Name Corporate Office 2018 Membership
1 California Regional MLS San Dimas, CA 96,203
2 Bright MLS Rockville, MD 88,071
3 Stellar MLS Maitland, FL 58,600
4 MIAMI Association of Realtors (SEF Shared MLS Database) Miami, FL 50,019
5 Midwest Real Estate Data Lisle, Il 45,000
6 First Multiple Listing Service Atlanta, GA 42,438
7 MLS Property Information Network Shrewsbury, MA 41,537
8 New York MLS (Combined MLSli/HGAR MLS) West Babylon, NY 40,000
9 Georgia MLS Tucker, GA 39,209
10 North Texas Real Estate Information Systems Dallas, TX 38,522
11 Arizona Regional MLS Tempe, AZ 38,321
12 Houston Association Of Realtors Houston, TX 35,844
13 RAPB + GFLR (Beaches MLS) West Palm Beach, FL 33,204
14 Northwest MLS Kirkland, WA 30,984
15 REcolorado Greenwood Village, CO 24,113
16 Garden State MLS Parsippany, NJ 23,061
17 Metrolist Services Sacramento, CA 20,498
18 RMLS of Minnesota (Northstar MLS) St. Paul, MN 18,097
19 SMART MLS Wallingford, CT 17,762
20 Realcomp Farmington Hills, MI 16,729

What is an MLS?

multiple listing service (MLS, also multiple listing system or multiple listings service) is a suite of services that real estate brokers use to establish contractual offers of compensation (among brokers) and accumulate and disseminate information to enable appraisals. A multiple listing service’s database and software is used by real estate brokers in real estate (or aircraft broker[1] in other industries for example), representing sellers under a listing contract to widely share information about properties with other brokers who may represent potential buyers or wish to work with a seller’s broker in finding a buyer for the property or asset. The listing data stored in a multiple listing service’s database is the proprietary information of the broker who has obtained a listing agreement with a property’s seller.

According to the U.S. National Association of Realtors:

In the late 1800s, real estate brokers regularly gathered at the offices of their local associations to share information about properties they were trying to sell. They agreed to compensate other brokers who helped sell those properties, and the first MLS was born, based on a fundamental principle that’s unique to organized real estate: Help me sell my inventory and I’ll help you sell yours

There is no single authoritative MLS and no universal data format. However, there is a data standard for MLS systems—the Real Estate Transaction Standard—which is being deployed across MLS solutions in North America. However, the Real Estate Standards Organization has been spearheading the industry’s move to use more modern data formats, standard data definitions/fields, and coordinate leading industry organizations to build a new future of real estate data.

Each MLS in the U.S. are independent and offers direct data feeds to technology vendors via RETS and/or Web API. Our proprietary MLS aggregation technology connects your local MLS into our IDX engine and the most advanced home search available.

We deal with technology, so you do not have to, and we love geeking out on innovative technology that people use every day. How much do we love data and software people love? The Real Estate Standards Organization (RESO) wrote a case study on us, how our team helped build the navigation apps in your car and on your phone (pages 6 – 7, and Showcase IDX’s role in the real estate industry over the past 20+ years.

Start your free trial today. Find out why we’re the #1 rated IDX plugin and why the best web developers work with us.

Get the website you deserve

Don’t Just Take Our Word For It

An IDX Feed That's Above The Rest!

Showcase IDX is a better solution in regards to search rankings. I love the hot sheets and the simplicity to create "hot sheets" for different areas.

Head and shoulders above the rest, and it's really not even close.

Showcase IDX is head and shoulders above the rest, and it's really not even close. We fully expect more of the agents and brokers we work with to love the value and flexibility Showcase IDX provides, especially as results our current users are seeing continue to improve.

What I have been looking for all along.

I have used both Diverse Solutions and IhomeFinder. Neither delivered what I wanted. Since switching to Showcase, my bounce rate is down 20%, time spent on my site has doubled, and most importantly I am getting 4x more registrations on my site.

Converts website leads at a high level

Showcase IDX is leading the way in the world of WordPress IDX solutions. Clients love utilizing the Showcase IDX product with original features not found in any other product.

Best WordPress IDX, period.

Simple to use (i.e. low bounce rates and high user engagement), great mapping with polygon search, fantastic mobile responsive functionality, ‘login with facebook’, ultra-fast, and they are always adding or updating functionalities.


Since switching to Showcase, registrations and customer interaction have increased tremendously. Showcase is so much cleaner than just using our own MLS systems...easy to use even for a beginner starting their own website.

Showcase IDX brings the leads!

I am very happy to say Showcase IDX delivers the leads! I am often told by prospects and clients that our website is their favorite in town. A large amount of business is generated through our website presence.

Best IDX Solution out there

No solution even compares with what Showcase IDX offer. There is no way I would steer clients towards any other solution.

Best IDX plugin by far!

Showcase IDX is now the only IDX I recommend to my clients. Visually, it is stunning and so much better than the other IDX’s. To top it off, customer service is top notch

Your retention rate will be much higher

No subdomains or Iframes is probably my favorite feature, but at the end of the day it's about Results. I think the biggest thing is how "sticky" their site becomes. With Showcase IDX, the retention rate is much higher.

Showcase IDX Support Team Rocks

Showcase IDX has a streamlined interface and easy to navigate features that don't clutter our website or lock us into particular themes. But where they really shine is in their customer service.

The Best All-Around IDX For Realtors Wanting Results

We were previously using another IDX for our client sites. As a digital agency focused on measurable results, we were frustrated with the limitations we had. We started researching alternatives and thank god we found Showcase IDX.

Showcase IDX all day everyday!

by far the best IDX solution out there. Forward thinking, always improving, with a clear focus on the interface - one of the major areas other providers fail. It feels like everyone else is still playing catch-up all these years later.

I switched from IDX Broker

I get more voluntary sign ups than I did with old provider. I think that speaks for itself.

Would You Bet Your Business On A IDX Solution?

We effectively compete every day with Zillow, Trulia and Redfin. Showcase Idx is critical to our success...Our site stats are over 12K unique users per week. That is up significantly from a year ago when we were on Wolfnet Idx.

Author Details
Chief Marketing Officer
Entrepreneurial marketing leader that’s built and run organizations from start-up to over $500M annual revenue. He brings a unique combination of storytelling and innovation to the team, having led marketing for many brands. Kurt’s a regular conference speaker and workshop leader around modern marketing tactics that actually drive sales. In addition, he has been asked to coach and advise thousands of leaders, from startup founders to the President of the United States.



Join Our Support Team For A Live Demo

Join our support team for a live demo on the leading wordpress plugin for real estate websites.

Get Your Copy Now

Copyright 2020 SHOWCASE IDX  ©  All Rights Reserved