Open houses on internet sites

Realtor.com and Homesnap both display open house information directly from Matrix. 

Additionally, many IDX/brokerage sites (Zillow, Elliman, Raveis, Pitt, BHHSNE, etc.) display open house information as well. 

We have not checked all IDX sites, but the major brokerage sites seem to include open house information.

Open house information can take anywhere from 15 minutes to 48 hours to appear on 3rd party sites. The refresh/update cycle depends on the individual site (unfortunately, SmartMLS has no influence over how often 3rd party sites update their data).