Is Zillow's home value estimate accurate?

Zillow's Zestimate and similar tools from other sites are automated valuation models (AVMs). They analyze publicly available data, including tax records, prior sale prices, listing history, and comparable transactions, to generate an estimated value range. That's a meaningful amount of information, and for some properties in some markets, these estimates come reasonably close to what buyers are willing to pay.

What automated estimates can't do

An algorithm can't walk through your home. It doesn't know about the kitchen you renovated last year, the roof you replaced, or the fact that your lot backs up to a greenway that buyers in your area specifically search for. It also doesn't know about the condition of the comparable properties it's drawing from, or how quickly buyer demand is shifting in your specific neighborhood.

Property data can also be incomplete or delayed. In markets where homes are moving quickly or inventory is unusually low, automated estimates can lag behind current conditions.

How this differs from a CMA

A Comparative Market Analysis (CMA) is prepared by a Realtor who has actually seen your home and has current, direct knowledge of what buyers in your price range are choosing. The agent considers not just sold prices, but the specific characteristics of each comparable property, how your home compares, current competition, and market conditions at the time of the analysis.

A CMA is still an informed estimate, not a guarantee of what your home will sell for. But it's grounded in property-specific context that an automated model can't replicate.

The practical takeaway

Online estimates are reasonable for a general sense of where your home might fall. If you're actively thinking about selling, a conversation with a local agent and a current CMA will give you a more complete picture of what today's market suggests buyers may pay.