Zestimate Accuracy: What You Need to Know

If you’ve ever looked at a home on Zillow, you’ve probably seen the bold number called a "Zestimate." It’s meant to be an instant guess of a property's market value. But can you trust it? The short answer is: sometimes, but not always. Let’s break down how Zillow comes up with that figure, why it can be off, and what you can do to make it work better for you.

How Zillow Generates a Zestimate

Zillow pulls data from public records, recent sales, tax information, and even user‑submitted details. It then runs a computer model that looks at things like square footage, number of bedrooms, neighborhood trends, and recent comparable sales. The algorithm tries to find patterns that predict price. Because it’s all data‑driven, the Zestimate can change daily as new information rolls in.

In most markets, Zillow says its median error rate is around 5% for homes that are on the market and about 7% for off‑market homes. That sounds decent, but those numbers hide a lot of variation. In some neighborhoods the error can be under 2%; in others it can exceed 15%, especially where there aren’t enough recent sales to train the model.

Tips to Improve Your Zestimate Accuracy

1. Update your home’s facts. Log into Zillow, claim your property, and add any recent renovations, upgrades, or missing rooms. The more accurate the input, the closer the output.

2. Check recent sales. Look at the sale prices of houses that truly match yours – same size, same age, same lot. If they differ a lot from the Zestimate, treat the number as a starting point, not a final answer.

3. Watch the market. In fast‑moving markets, prices swing quickly. A Zestimate based on data from two months ago might be outdated. Keep an eye on local news and recent listings.

4. Consider the lawsuit buzz. Zillow has faced legal challenges over its estimates, most notably the 2025 lawsuit alleging that some Zestimates were misleading. While the case is still unfolding, it highlights that the numbers aren’t guaranteed.

5. Use a professional appraisal. If you’re serious about buying, selling, or refinancing, hire an appraiser. They’ll walk the property, compare real‑time comps, and give you a figure that lenders accept.

Remember, the Zestimate is a tool, not a verdict. It’s great for getting a quick ballpark figure, but you should always double‑check with local data, a real‑estate agent, or an appraisal, especially if you’re making a big financial decision.

Bottom line: Zillow’s algorithm is getting smarter, but it still relies on the quality of the data it receives. Keep your listing info up to date, compare with nearby sales, and treat the Zestimate as a helpful guide rather than the final word.