What is IDX?

IDX is an acronym for Internet Data Exchange, which enables real estate professionals to display the most comprehensive and up-to-date property listing data on their own real estate websites.

Established by the National Association of REALTORS®, IDX is a policy under which brokers exchange permission to display one another’s listings on the internet. Broker Reciprocity is another name used for IDX, reflecting this cooperative exchange between brokers.

Although IDX is a policy, the term is commonly used to refer to the data feed of listings provided by an MLS® System. IDX also includes a set of rules for how listing data is displayed, and each MLS® System can have variations in these rules.

MLS® is an acronym for Multiple Listing Service®, which is a proprietary database created, maintained and paid for by real estate professionals to help their clients search for, buy, and sell property. MLS® Systems are the source of IDX listing data and can serve one association or board or multiple associations or boards. An MLS® System may be owned by REALTORS® associations and/or brokers, or it may be an independent entity. The geography each MLS® System covers can range from an individual city or county to large regions.

Our IDX Coverage page provides detailed information about the different MLS® Systems for which we currently provide service. (As local or regional boards manage IDX data sets and access policies, please use the name of your association when searching for your system on our coverage page, rather than looking for a product name such as Flexmls, MatrixTM, or Navica.)

The National Association of REALTORS® website provides more information about MLS® Systems.

* In Canada, the trademarks REALTOR®, REALTORS® and the REALTOR® logo are controlled by The Canadian Real Estate Association (CREA) and identify real estate professionals who are members of CREA. The trademarks MLS®, Multiple Listing Service® and the associated logos are owned by CREA and identify the quality of services provided by real estate professionals who are members of CREA. The trademark DDF® is also owned by CREA and identifies CREA’s Data Distribution Facility (DDF®).

Real estate board MLS® Systems make property listing data available to IDX vendors, such as clickIDX, via an IDX data feed. We use the industry standard RETS protocol in most of the MLS® Systems we serve. We provide FTP IDX in some areas, although we no longer add new data feeds using FTP. (FTP does not allow for data management as efficiently as RETS.) We do not offer IDX via frameable links or smartframe links from an MLS® System.

IDX companies typically download updated property data from an MLS® System several times per day, store it in a database, and make it available for search and display on their clients’ websites. In some areas, agents and brokers might be able to get a direct IDX data feed from their MLS® System, although they would then need to implement a costly system, with professional programming skills, for downloading, storing and displaying the data.

IDX is only available for members of Real estate board MLS® Systems for display on their websites. Vendors like clickIDX cannot provide IDX to non-members or for purposes other than member website display.

In most boards, agents and brokers can have IDX on their own websites, as can teams of agents and entire offices. Some boards only allow IDX for brokers and offices, not agents. In all areas, IDX accounts cannot be shared by agents or brokers in different brokerage offices, as each IDX website needs to be licensed under one designated local broker.

You need to fill out IDX paperwork, normally with broker signature, and be approved for clickIDX by your real estate board before we can provide listings for your website. This can take a couple of business days to complete after you sign up for a paid account and return your paperwork to us (or longer in some boards). We’ll automatically email you full instructions for your board when you become a paying client.

IDX allows you (as an agent or broker member of a real estate board that operates an MLS® System) to show listings from throughout that board on your own website, via an IDX data feed that automatically updates every few hours.

Companies like Zillow and Trulia do not use IDX. Instead, they receive listings from various sources, including brokerage syndication, and in limited cases, from MLS® Systems, and aggregate them on their portal websites. The listing information on portal sites is often not as comprehensive or as up-to-date as IDX data. For example, studies have shown that upwards of 30% of the listings on Zillow and Trulia were no longer for sale, and about 20% of active listings in MLS® Systems were missing on these sites.

Also, portal sites usually aim to provide leads to agents who sponsor individual listings, or to the listing agent or listing office for each listing. IDX, meanwhile, is designed to allow you to get the leads from all listings on your site, and to encourage consumers to contact you for information about available properties.