If you’re wondering how accurate the Zillow Zestimate is in Seattle, Zillow reports a 6.09% median error for off-market homes in the Seattle metro. In HomeLight’s review of 29 recently sold Seattle homes, the median pre-listing Zestimate differed from the final sale price by 5.4%. That makes a Zestimate a useful reference point, but not necessarily the number you should use to price your home. Below, we break down Zillow’s accuracy data and show how pre-listing Zestimates compared with actual Seattle sale prices. Current Zillow Group data for the Seattle metro reports the following: For a $1 million home, 6.09% represents $60,900. Here’s how that percentage translates at several home values: A median error is not a guaranteed margin of error. Half of Zillow’s measured errors are smaller than the median and half are larger. The off-market numbers are particularly relevant if you haven’t listed your home yet. Just 42.91% of Seattle-area off-market Zestimates fall within 5% of the closed sale price. Once a home goes on the market, Zillow has more information to work with. Its model can incorporate the asking price, listing description, comparable homes, and days on market, which helps explain why Zillow reports lower errors for listed homes. For active listings, Zillow measures accuracy by comparing the last Zestimate shown before a home goes pending with the final recorded sale price. Our HomeLight analysis asks a different question: How close was the Zestimate before the home was listed and Zillow had that additional market information? HomeLight reviewed 29 homes that recently sold within Seattle city limits. For each property, we compared the last available Zestimate before the home was listed with its final closed sale price, then calculated the percentage difference and whether Zillow estimated the home above or below its final sale price. Zillow says historical Zestimates reflect information available at that point in time. It can occasionally recalculate historical Zestimates following major model or data updates, but says future transaction information isn’t used to influence an earlier historical estimate. Methodology: HomeLight reviewed 29 recently sold homes within Seattle city limits. For each property, we compared the last historical Zestimate available before the home was listed for sale with its final closed sale price, then calculated the absolute percentage difference between the two. This sample is illustrative and is not statistically representative of all Seattle homes. Among the 29 recently sold Seattle homes HomeLight reviewed, the median absolute percentage error between the pre-listing Zestimate and sale price was 5.4%. The median absolute dollar difference was $51,100. Just under half of the Zestimates — 48.3% — came within 5% of the final sale price. About 86.2% were within 10%, and all 29 were within 20%. Zillow’s estimate came in higher than the final sale price for 16 homes and lower for 12. One Zestimate matched the home’s sale price exactly. The results also showed a wide range from one property to another. The closest Zestimate in our sample was right on the sale price, while the largest miss was 18.2%, or $200,000 above what the home ultimately sold for. For comparison, Zillow Group reports a 6.09% median error for off-market homes across the Seattle metro, with 42.91% falling within 5% of the sale price. To show what the differences looked like in actual dollars, we selected five homes from our sample representing the closest estimate, the lower quartile, the median result, the upper quartile, and the largest miss. A positive difference means the pre-listing Zestimate was higher than the eventual sale price. A negative difference means the Zestimate was lower.
Zillow says its Zestimate is an automated estimate of a home’s market value, not an appraisal. Its model draws from sources that include public records, MLS feeds, property details, previous sales, market trends, and information supplied by homeowners. But the data available to an automated model may not capture everything that affects what a buyer will pay. Zillow says unreported additions, updates and remodels may not be reflected in its estimate. Views, lot usability, street location, walkability scores, interior condition, and the quality of improvements may also be difficult to capture fully. And automated valuation models rely heavily on available comparable sales. A Seattle home that is unusual for its area or has relatively few recent comps may be harder to estimate accurately. As with any real estate value estimate, the quality and completeness of the information can affect the result. This is even true for professional appraisals. When you’re estimating what your home might sell for, it can help to compare more than one valuation, especially when the numbers disagree. HomeLight’s Home Value Estimator takes a somewhat different approach. In addition to pulling property, sales, and market data, the tool asks eight questions about the home, including its kitchen, bathrooms, main living space, curb appeal, upgrades, and extras. Those questions can capture details that may not be apparent from public records. For example, two homes may have the same bed and bath counts even though one has a recently remodeled kitchen or newer HVAC system. Homeowners can also receive a free introduction to a top 5% agent in their ZIP code. An agent can provide a comparative market analysis (CMA) based on similar local sales, the condition of your home, and current buyer demand. »See what your Seattle home could be worth now If your Zestimate seems noticeably higher or lower than expected, you can also:
In HomeLight’s 29-home Seattle sample, the median pre-listing Zestimate differed from the eventual sale price by 5.4%. That suggests a Zestimate can be informative, but it shouldn’t automatically become your listing price. If you’re considering selling, compare your Zestimate with another estimate and recent comparable sales. HomeLight’s Home Value Estimator can provide another perspective, while a local agent can give you a more detailed opinion based on the property and today’s Seattle market.Seattle metro Zestimate accuracy
On-market homes
Off-market homes
Median error
1.56%
6.09%
Within 5% of sale price
88.20%
42.91%
Within 10% of sale price
97.31%
69.05%
Within 20% of sale price
99.65%
89.12%
What does a 6.09% Zestimate median error mean in dollars?
Home value
6.09% of value
$750,000
$45,675
$1 million
$60,900
$1.5 million
$91,350
We tested Seattle Zestimates against actual sales
What our Seattle Zestimate test found
Five Seattle Zestimate examples
Seattle home
Pre-listing Zestimate
Sold price
Difference
Error
2141 7th Ave. W
$1,600,000
$1,600,000
$0
0.0%
1119 16th Ave.
$1,100,000
$1,125,000
-$25,000
2.2%
5305 SW Orleans St.
$898,900
$950,000
-$51,100
5.4%
11311 31st Ave. NE
$651,500
$598,000
+$53,500
8.9%
1961 31st Ave. W
$1,300,000
$1,100,000
+$200,000
18.2%
Why can a Seattle Zestimate be off?
Get another opinion on your home’s value
Is a Zestimate enough to price your Seattle home?
