Zillow uses artificial intelligence to estimate home values, and this is based upon a pool of recent home sales, within a specific geographic location, that share similar characteristics, such as bedroom count, number of baths, square footage, etc. The resultant conclusion can be indicative of a value price-range where most other characteristics are highly similar (such as age, construction quality, location, view) . However, the credibility of the value conclusion diminishes and becomes unreliable in neighborhoods where property characteristics vary, especially in areas where esthetic and/or other priorities dictate value, such as city views, usable yards in hillside locales, and where there is a mix of unique, high-quality vintage, and custom built residences. I often hear from panicked clients that Zillow has under-estimated the value of their homes - and sometimes I hear the opposite..and they're stunned. In both cases, it is always in neighborhoods that are anything but homogenous.