Why do home value estimates differ so much between websites?
Because each site runs a different model on different data with a different refresh schedule. One leans on county assessments, another on recent nearby sales, another on its own listing history; some update daily, some quarterly. Since your home is off-market while you check, every model is extrapolating — and different extrapolations land tens of thousands of dollars apart. The spread between sites is itself useful information: it approximates the honest uncertainty.
Reviewed · Reviewed by Kristian Peter, CA DRE #01308663
County assessment data — the backbone of most models — varies enormously in quality by county, and in several states assessed value is legally a fraction of market value, which a model must correct for. A model strong in California can be weak in Texas for reasons invisible to the person reading the number.
A practical way to use the disagreement: collect two or three estimates, note the lowest low and the highest high, and treat that as your genuine range going in. Then let pricing sharpen it — agents competing for your listing each stake a projected price with comparables attached, which converts the model spread into defended local judgments.
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Why asking for a home value online triggers weeks of agent calls, how lead-generation sites monetize your phone number, and how to research value and hire an agent without being sold.
Guide · Home valueHow Do I Know What to Sell My House For?How to figure out what to sell your house for: market value versus list price, where the number comes from, and whether you can price above or below the market on purpose.