IDX – What Does It Mean In Real Estate Speak?

Real Estate Agent with Silicon Beach Properties • KW CalBRE #01712960

Fellow rainer Angie Vandenbergh recently put up a couple of posts debating whether IDX is a database, a technology or a policy.  Below is my take on the distinctions after five years of developing and selling IDX solutions.

First Up -- The Basics

Quite literally, IDX stands for "Internet Data Exchange."  More loosely, it translates to "serving up databases to websites."  In the case of real estate, that means bringing listings databases from MLS's to agent and company websites.

Despite what you'll see on Wikipedia, IDX is not a real estate industry-specific term, as you can see with a simple Google search.  But then, Wikipedia is not an objective research tool.  Anybody can edit a Wikipedia entry.  Prospective editors don't even have to log in to edit articles.

While the term "IDX" is heavily associated with the real estate industry, I've also seen it in relation to the healthcare industry.  I haven't researched the healthcare angle extensively, but from what I've seen, IDX in the healthcare context relates to serving up electronic medical records to private intranets.

But I digress to tech talk.  Sorry.

So, is IDX a database, a technology or a policy?

Is "IDX" A Database?

Each MLS has (or under the 2002 NAR mandate is supposed to have) an IDX database.  This is the database approved for "exchange" with agent and company websites (i.e., approved for Internet display), but this database is not the"IDX."  It is the "IDX database," and this database is almost never (if ever) exactly the same as the MLS database.  The NAR policy was designed originally as a marketing initiative, not to create virtual agents.  While each MLS decides what data to put in its IDX database, the data provided generally represents just the barest of facts about the listings -- enough to whet a consumer's appetite for more and to spur contact with an agent.  Around my office, we call IDX "MLS Lite." 

Also, there is always some broker who opts his/her/its listings out of the local IDX program, meaning that the IDX database rarely, if ever, has 100% of the MLS's listings in it.  When searching an IDX database, therefore, consumers are getting less than all listings and relatively few facts about the listings that they are seeing.  Proceed with caution if you're calling this an "MLS Search" on your website.  This is a misrepresentation and some MLS's will pop you for it.

Okay, I'm digressing again.  My primary point is that "IDX" is an exchange of data, not a "database."

Is "IDX" A Technology?

Is IDX a technology?  No, it takes technology to bring that database to websites, but "IDX" is not a technology in and of itself.  Databases don't just swim over to websites.  Programming applications are needed.  When the NAR issued its IDX mandate in 2002, it didn't tell MLS's that they had to actually deliver data to member websites.  The NAR simply said that MLS's "shall" make the data available.  This left the field wide open for private vendors, like our company to supply applications.  Later, MLS's started offering their own applications, although these solutions are not generally as robust in terms of functionality as private solutions.

Is "IDX" A Policy?

Is IDX a policy?  No, but a wide misunderstanding of the nuances has led many in real estate to shorthand policies regarding IDX as "IDX."  Heck, after I wrote this post originally, I found myself making the same sloppy references in client emails and marketing copy, so I'm as guilty as the next person of muddying the waters.

Why Does It Matter?

Database, technology or policy?  Do any of these distinctions matter?  Not terribly, but from where I sit as an IDX vendor who talks regularly to agents and brokers all across the country and spends countless more hours studying agent and broker websites, I see basic misunderstandings about IDX that lead agents and brokers to make marketing decisions that don't serve their highest marketing objectives.  With this post, I wanted to weigh in with a few of the basics so agents and brokers can compare apples to apples and ask a few more hard questions to their potential IDX vendors, including their MLS's.

The most important thing that I hope you take away from my companion posts today is a strong understanding that IDX databases represent an incredibly powerful tool for online marketing and lead incubation.  These databases are, however, sadly and drastically under-utilized by most agents and brokers.  Can one woman on a soapbox make a difference?  I hope so. 

For more on the topic of leveraging IDX databases to grow business, see my companion post What Has Your IDX Done For You Lately?

To your unlimited online marketing success!

Posted by



Tracy Thrower Conyers
Silicon Beach Properties • KW, CalBRE #01712960
m: 424.272.1339 | w:

buy. sell. lease. residential in silicon beach.

Comments (9)

James Gordon
Sibcy Cline Realtors® - Cincinnati, OH
My board does not allow IDX feeds to agents without the brokers permission.
Aug 01, 2007 10:38 PM
Patsy Ittner, Your Premier Broker Selling St. Augustine Real Estate
Little Fox Realty - Saint Augustine, FL
This is an excellent, information post, and I learned from it, which is the point.  Thank you for this. 
Aug 04, 2007 07:40 AM
Edward Walker
Mel Foster Co. - Bettendorf, IA
It is amazing the difference from one board to another.  We have listings from four different MLS's and getting ready to add two more.  In one, everyone has opted out so we will only be showing ours.  In another, no data can be shared without  have the entire IDX behind a registration/firewall.  Our main one says - who cares - let the consumer have the information.
Aug 05, 2007 07:44 AM
Tracy Thrower Conyers
Silicon Beach Properties • KW - Venice, CA
buy. sell. lease. residential in silicon beach.

James, smart brokers readily give permission.  Why wouldn't he or she support full exposure for your client's property?

Thank you, Patsy!  Let your colleagues know about the post.  The more that agents and brokers know about IDX, the more they can affirmatively shape the policies behind it.

Edward, it's a good thing the smart MLS is your primary marketing area.  =-)

Aug 06, 2007 03:21 AM
Gary Miljour
American Financial Network, Inc. NMLS#207208 - Southern Pines, NC
Mortgage Originator NMLS Licensed in AZ and NC
I just wanted to let you know I link this post to my recent one.  Just an FYI
Aug 25, 2007 05:24 AM
Tracy Thrower Conyers
Silicon Beach Properties • KW - Venice, CA
buy. sell. lease. residential in silicon beach.
Thank you, Gary!  I appreciate your support and applaud you for the message in your post.
Aug 25, 2007 04:17 PM
Margaret C. Taylor
Century 21 New Millennium MD - Mechanicsville, MD
St Marys/Calvert/Charles MD Real Estate Agent

No one has commented for over two years.  Is this information still good?  Sorry I'm new and very low tech.  I'm trying to learn everything I can as quickly as possible to boost my business!  This is still going over my head!  How do I know if the MLS on my website exchanges data with IDX.  Is this the write teminology?  My website is at   MargaretC.

Jan 01, 2010 02:42 PM
Jen Edwards
RE/MAX Unlimited - Ponte Vedra Beach, FL
Broker Associate

Good clarification and still relevant two years later !

Nov 29, 2010 02:41 PM
Lynn B. Friedman CRS Atlanta, GA 404-939-2727
Atlanta Homes ODAT Realty - Love our Great City - Love our Clients! Buckhead - Midtown - Westside - Atlanta, GA
Concierge Service for Our Atlanta Sellers & Buyers

Dear Tracy,

Thanks for the clear explanation. I wish I could re-blog this in 2014! Since I cannot, I will link back to your post!

Have a happy day -

Jan 20, 2014 06:29 AM