Every online home value estimator we could read on October 30, 2026 describes its number as a computer-made estimate, and none presents it as an appraisal. Redfin says the Redfin Estimate "is not a formal appraisal," HomeLight calls its results "only approximations, not formal appraisals," and Opendoor calls its tool an automated valuation model that "does not inspect your home." An automated estimate is not an appraisal: an appraisal is an independent opinion of market value as of a stated date, developed by a licensed or certified appraiser under USPAP.
This page quotes each portal in its own words, links the page, and records the date it was read, because portal wording changes and a dated quotation can be checked. It belongs to the Online Estimates vs. Appraisals series, which starts from the pillar, Zestimate vs. Appraisal: What an Online Estimate Cannot See in Claremont.
What does Redfin say about the Redfin Estimate?
Redfin's page, About the Redfin Estimate, read on October 30, 2026, says it twice. First: "it is not an appraisal or a substitute for the expert pricing advice of your real estate agent." Second, in its questions and answers: "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."
The same page explains how the number is made, and those sentences matter as much as the disclaimer:
- "The Redfin Estimate is calculated by computers."
- "We use MLS data on recently-sold homes to calculate your property's current market value"
- "The Redfin Estimate algorithm determines comparable homes by looking for nearby homes that have recently sold and have similar features."
- "The Redfin Estimate only appears on single-family homes, townhouses, and condos with enough similar properties sold nearby within the last year."
Redfin also publishes its own accuracy figures there, separately for listed and unlisted homes. They change, so read them on the page itself.
What does Opendoor say about its estimate?
Opendoor's home value estimator page, read on October 30, 2026, answers the question "How does Opendoor estimate my home's value?" this way: "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 recorded data and nearby sales without anyone seeing the property.
On accuracy, the page says: "Accuracy depends on your home and the available data. The estimate may not reflect recent renovations, current condition, or unusual features."
The page has changed. When this site recorded it on September 28, 2026, its answer to whether the estimate was an appraisal read: "No. This is an automated valuation model (AVM), not a professional appraisal." By October 30, 2026 that answer was gone, and the page instead asked "Is this an Opendoor cash offer?" and answered "No. This is an estimated value range." Both points stand. A cash offer, a price a buyer will pay on stated terms, is not an appraisal either, and neither is the estimate that comes before it.
What does HomeLight say about its estimator?
HomeLight's home value estimator page, read on October 30, 2026, states: "In simple terms, these estimates are only approximations, not formal appraisals." It adds a short questionnaire about property type and condition, then says the result "may not fully account for recent upgrades, additions, or the unique characteristics of your home that only a human expert would notice."
The same page points sellers toward an agent's comparative market analysis or a professional appraisal for a fuller answer. A CMA, an agent's opinion of a likely list or sale price, is not an appraisal; it is a pricing tool, and it carries no appraiser's certification.
What about Zillow, Realtor.com and Homes.com?
On October 30, 2026, the Zillow Zestimate page and the Homes.com valuation page refused our automated request, and Realtor.com's page answered that too many requests had been made. None of the three is quoted here; read each portal's own page in a browser.
There is one dated primary record about the Zestimate. In Patel v. Zillow, Inc., No. 18-2130, decided February 8, 2019, the United States Court of Appeals for the Seventh Circuit described how the Zestimate worked and wrote: "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." The court also wrote that because Zillow "does not inspect the building, it cannot adjust for the fact that any given parcel may be more attractive and better maintained, raising its likely selling price, or the reverse." That is the court's 2019 description, not today's page.
What do the disclaimers have in common?
Read side by side, the portals agree on three things:
- A computer made the number. No person chose the comparable sales, a comparable sale being a closed sale of a similar property used as evidence of value.
- The inputs are records and nearby sales. That means the public record, what the county and listing services have on file about the house, plus recent sales the model treats as similar.
- Nobody went inside. Condition, renovations, additions and unusual features are named as the things the estimate may miss.
What none of them claims is just as telling. None states an effective date, the date the opinion of value applies to; an intended use, what the report will be used for; or intended users, the people entitled to rely on it. None measures gross living area, the finished, heated space above grade. None is signed by a licensed appraiser. Those are the parts an appraisal adds, and they are what a lender, a court, an estate's CPA or an assessment appeals board reads.
Why the gap is wide for a Claremont house
The disclaimers name renovations, additions and unusual features. Those are the features that define several Claremont pockets. Pre-1940 houses near the Village and the Colleges often carry enclosed porches and rear additions the record never caught. A permitted ADU and an unpermitted garage conversion look the same to a model. Claraboya and Padua Hills homes sell on view, grade and access, which no record field describes. And a sale across Mills Avenue in Montclair is in San Bernardino County, a different market a model may treat as next door. The Claremont area page describes those pockets.
Two companion articles go further: why each portal says its estimate is not an appraisal, and how to judge the estimator results for a Claremont house.
When a disclaimer becomes a problem
A portal estimate is a reasonable starting point for curiosity. It becomes a problem when it is used where a reader expects an appraisal: an estate or trust valuation, a divorce, a lender file, or a property tax appeal. The county's assessed value, the taxable value under California's assessment rules, is not an appraisal either. The estimate, CMA, assessment and appraisal comparison sets the four numbers side by side, and if the reader of your file expects an appraisal, you can request one or 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)
- HomeLight, Home Value Estimator: https://www.homelight.com/home-value-estimator (accessed October 30, 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)
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.
Frequently asked questions
Does any online home value estimator say it is an appraisal?
No. On October 30, 2026, Redfin said its estimate is not a formal appraisal, HomeLight called its results approximations rather than formal appraisals, and Opendoor described its tool as an automated valuation model that does not inspect the home. An appraisal is an independent opinion of market value by a licensed or certified appraiser.
Why quote the portal disclaimers with a date?
Because the wording changes. Opendoor's page answered the appraisal question directly on September 28, 2026, and by October 30, 2026 that answer had been replaced. A quotation with a link and a date can be checked; a paraphrase cannot.
What do the estimator disclaimers say the number cannot see?
They name current condition, recent renovations, additions and unusual features. Those are the things an appraiser records at the house and that public records often miss, especially on older homes with enclosed porches, rear additions or ADUs.
Can I use an online estimate for an estate, a divorce or a tax appeal?
The portals themselves say their estimate is not an appraisal, and the reader of those files usually expects one. Your attorney, CPA or the appeals board decides what evidence it accepts. Nothing here is legal or tax advice.
