- Blog - MLS & IDX


When potential home buyers click on a real estate website, they expect to see and want to be able to search through listings. That’s why visitor friendly, informative listings information is probably the main element in any real estate website. Good listings data makes the site useful for visitors and productive for realtors.


The sharing of listings information on real estate websites became available in early 2000 with the implementation of the Internet Data Exchange (IDX). This is the policy instituted by the National Association of Realtors (NAR) which authorizes realtors to display listings from other realtors on their sites.

(Note: You can find more information and the most current IDX Policy on the NAR website:

IDX-powered websites provide real estate listings information from the local MLS (Multiple Listings Service). IDX sites usually provide less detailed information than the full MLS because the data is limited to a sub-set allowed specifically for public display.

Two Real Estate Listings Delivery Methods

All real estate brokers participating in the Internet Data Exchange are granted special credentials by their MLS to access listings data. Some MLS organizations offer an IDX data license to IDX vendors. For example, our company, IDX Network, can access IDX data to put on realtor websites.

Other MLS groups offer a Broker IDX feed that can be used by company IDX vendors. Many MLS organizations offer both, vendor licenses and broker feeds.

IDX implementations and standards have changed drastically over recent years, as brokers and agents utilizing IDX services along with IDX vendors, have focused on the ability to optimize websites with IDX-driven
listings content. Most standard data exchange protocols for IDX information are FTP (File Transfer Protocol) or RETS (Real Estate Transaction Standard).


When data is delivered via the FTP feed, the MLS compiles the IDX subset of the MLS data as a set of files and puts it in a designated location on the server. IDX vendors can retrieve the files and use them in their own system. (FTP is the old way of delivering listings data and is actually on its way to becoming obsolete.)


Today, most MLS providers use the RETS protocol. RETS was created to overcome the difficulties presented by a large number of organizations desiring to share and distribute real estate information. RETS addressed this need by providing a common standard for the exchange of real estate data.

With a RETS data feed, the IDX vendor gets access to the database on an MLS RETS server. This allows vendors to select the frequency and type of updates that best serve their clients. However, the vendors receive
listings data “as is”. They have no control over data content. (Note: you can learn more about RETS technologies here:

The listings on real estate websites change as often as the IDX database updates do. The delivery of the data is a physical process between multiple networks. We work every day to deliver updated listings information to our clients’ websites.

Our Goal for Your Website

Our goal is to allow the updating system to generate accurate information to your site as quickly as possible. This means your website visitors will come back more often to view new listings that match their search criteria.

In addition, search engines prefer regularly updated data and will reward your site with better search engine rankings than competitors featuring stagnant data.