Redfin Estimate, Opendoor Estimate, Zestimate: Why Each Says It Is Not an Appraisal

The Redfin Estimate, the Opendoor estimate and the Zestimate are each a number a computer produces from recorded property data and nearby sales, without anyone going inside the house, and that is why none is an appraisal. Redfin says so in plain words. Opendoor's page calls its tool an automated valuation model that "does not inspect your home." A federal appeals court recorded that Zillow tells users none of the parcels has been inspected. An appraisal is something else: an independent opinion of market value as of a stated date, developed and signed by a licensed or certified appraiser under USPAP.

The exact wording of each portal, quoted and dated, is collected in what online home value estimators say about themselves. This article explains the reasons behind the words. It is part of the Online Estimates vs. Appraisals series.

Reason one: nobody has been inside the house

Each tool says, in its own way, that it has not seen the property.

• Redfin. On October 30, 2026, Redfin's page said: "Like other estimates, the Redfin Estimate is not a formal appraisal or substitute for the in-person expertise of a real estate agent or professional appraiser." It also says: "The Redfin Estimate is calculated by computers."
• Opendoor. On the same date, Opendoor's page said: "Our automated valuation model uses available property data and comparable homes to estimate a value range. It does not inspect your home or collect details about its current condition." An automated valuation model (AVM) is a computer program that estimates value from data without anyone seeing the property. When this site first recorded the page on September 28, 2026, it also said: "No. This is an automated valuation model (AVM), not a professional appraisal." That sentence was gone by October 30, 2026.
• Zillow. Zillow's Zestimate page refused our automated request on October 30, 2026, so it is not quoted here. In Patel v. Zillow, Inc. (2019), the Seventh Circuit wrote that "Zillow informs users that none of the parcels has been inspected and that Zestimates may be inaccurate, though Zillow touts them as useful starting points."

An appraiser measures the house. Gross living area, the finished, heated space above grade, comes from the appraiser's own exterior measurements, not from the public record, which is what the county and listing services have on file. Condition, updating, additions and permit history are recorded room by room. A model reads fields in a database; an appraiser reads the house.

Reason two: an appraisal is a regulated professional opinion

In California, appraisers are licensed by the Bureau of Real Estate Appraisers, and an appraisal report carries the appraiser's signed certification and license number. The Uniform Standards of Professional Appraisal Practice set how the opinion is developed and reported. A portal estimate has no signer, no license number and no certification.

The law also sorts the two into separate boxes. Federal statute, 12 U.S.C. section 3354, defines an automated valuation model as "any computerized model used by mortgage originators and secondary market issuers" to determine "the collateral worth of a mortgage secured by a consumer's principal dwelling," and requires quality control standards for those models. Six federal agencies adopted those standards in a final rule effective October 1, 2025. AVMs get their own rules because they are not appraisals.

The Patel case shows the same line from another side. The opinion notes that the district judge had concluded an automated valuation model differs from an appraisal as a matter of law under the Illinois licensing statute; the appeals court affirmed on a different ground and did not decide that point. That is Illinois, not California, and it is not legal advice; it simply shows that the distinction the portals draw is one courts and legislatures draw too.

Reason three: an estimate answers a different question

Each estimate sits beside the company's own business, and each page says what it is for. Redfin points owners to its agents for pricing advice. Opendoor separates its estimate from its cash offer; its page answers "Is this an Opendoor cash offer?" with "No. This is an estimated value range." A cash offer, a price a buyer will pay on stated terms, is not an appraisal either. A CMA, an agent's comparative market analysis of a likely list or sale price, is not an appraisal. Neither is the county's assessed value, the taxable value under California's assessment rules.

An appraisal answers a question someone else will read: a lender's underwriter, a probate court, a trustee, a family law attorney, an assessment appeals board. That is why it states its intended use, what the report will be used for, and its intended users, the people entitled to rely on it.

Reason four: an estimate has no effective date you can choose

An online estimate describes today, more or less, and it moves when new sales are recorded. An appraisal states an effective date, the date the opinion of value applies to. For an estate that date is usually the date of death, which makes the work a retrospective appraisal, an appraisal whose effective date is in the past. No portal offers a value as of a date you choose. The date-of-death appraisal explainer shows why that matters to heirs and their CPA.

Why the three tools give three different numbers

Each model draws on its own data and picks its own comparable sales, a comparable sale being a closed sale of a similar property used as evidence of value. Redfin says its algorithm looks "for nearby homes that have recently sold and have similar features," and lets owners create an "Owner Estimate" with comparable homes they select. Different inputs, different numbers. Picking the number you like best does not turn any of them into an appraisal. What an automated valuation model is and is not covers the method in more depth.

What this means for a Claremont house

The portals name current condition, renovations and unusual features as the things they may miss. In Claremont those things decide value in whole pockets: enclosed porches and rear additions on pre-1940 houses near the Village and the Colleges, permit status on ADUs, view, grade and access in Claraboya and Padua Hills. A model can also reach across Mills Avenue into Montclair, which is San Bernardino County, a different assessor and a different buyer pool. The Claremont area page describes each pocket, and the pillar, what an online estimate cannot see in Claremont, walks through them house by house.

If the reader of your file expects an appraisal, start with the side-by-side comparison of an estimate and an appraisal, then call (909) 324-6122. Fees are set by the scope of the assignment and quoted before work begins, and they do not depend on the value.

Sources

• Redfin, About the Redfin Estimate: https://www.redfin.com/redfin-estimate (accessed October 30, 2026)
• Opendoor, Home Value Estimator: https://www.opendoor.com/home-value-estimator (accessed October 30, 2026; earlier wording recorded September 28, 2026)
• Zillow, Zestimate: https://www.zillow.com/zestimate/ (accessed October 30, 2026; the page refused the automated request and is not quoted)
• United States Court of Appeals for the Seventh Circuit, Patel v. Zillow, Inc., No. 18-2130 (February 8, 2019), via GovInfo: https://www.govinfo.gov/content/pkg/USCOURTS-ca7-18-02130/pdf/USCOURTS-ca7-18-02130-0.pdf (accessed October 30, 2026)
• 12 U.S.C. section 3354, Automated valuation models, via Legal Information Institute: https://www.law.cornell.edu/uscode/text/12/3354 (accessed October 30, 2026)
• Consumer Financial Protection Bureau, Quality Control Standards for Automated Valuation Models (final rule): https://www.consumerfinance.gov/rules-policy/final-rules/quality-control-standards-for-automated-valuation-models/ (accessed October 30, 2026)

Gordon Hall, California Certified Residential Real Estate Appraiser, BREA No. AR003877 (lookup: https://www2.brea.ca.gov/breasearch/faces/party/view.xhtml?id=23601). Reports are prepared in conformity with the Uniform Standards of Professional Appraisal Practice (USPAP). Nothing here is legal or tax advice; admissibility is always the court's decision.