Internet Data Exchange (IDX) is an umbrella term used to cover policies, standards, and software pertaining to the display of real estate listing information on websites.
How IDX Works for Buyers
IDX is the software used by real estate professionals to add MLS listings to their website.
IDX establishes a data connection between your website and the MLS, imports listings, and displays them on your website. The listings are updated every few hours, so Buyers always have access to the most recent listings and can contact the consultant for information about the available properties in the Reno/Sparks area.
On the other hand, web portals like Zillow and Trulia don’t use IDX. They get their information from other sources, including brokerage syndication. That’s why you’ll find the listings on portal sites are often not as comprehensive or as up-to-date as IDX data.
Read more here.