Our MLS can take up to 24 hours, though usually no more than a few. The photos need to be reviewed by the MLS to insure compliance with all rules and regulations before they post, nothing pornographic, etc.
After that they are fed through the IDX (Internet Data Exchange) to Realtor.com and a host of other websites which also includes other real estate company websites. This process can take many days. I tell my clients it can take a week for everything to filter out through the Internet. Also, the Internet is like the Wild West. Once the listing information gets out there we often have little or no control as to how data is formatted, which data is displayed, where it ends up, or whether all of it is accurately displayed.
I once found one of my listings inaccurately combined with information from another Realtorâ€™s listing on a website in Poland (in Polish).