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Part of: Square Footage in Real Estate: The Complete Guide

How Accurate Is Redfin Square Footage? What Buyers Need to Know

Redfin is known for being more data-forward than most real estate portals, but its square footage figures come from the same sources as everyone else: county assessor records and MLS data feeds. That means the same accuracy problems exist. Here is what buyers and sellers need to understand before relying on Redfin's numbers.

Source	Where the data comes from	Typical accuracy
Redfin	MLS (active) or county assessor (off-market)	±5–15% vs measured GLA
Zillow	County assessor or MLS feed	±5–15% vs measured GLA
County assessor / tax records	Historical permit data, often not updated	±5–20% vs measured GLA
MLS listing	Agent-entered — self-reported, varies widely	±3–10%, agent dependent
Professional appraisal	Exterior ANSI Z765 measurement	±1% — most accurate

Where Redfin gets its square footage data

Redfin is a licensed real estate brokerage with direct access to MLS feeds in most markets. For active listings, Redfin displays the square footage entered by the listing agent in the MLS. For off-market properties, it falls back to county assessor records and tax roll data.

This is the same data hierarchy used by Zillow and Realtor.com. The distinction that matters: Redfin often gets MLS data faster and more completely than Zillow in markets where it operates as an active brokerage, because it has direct MLS access rather than relying on third-party data aggregators. But that only helps if the MLS figure itself is accurate, which it frequently is not.

Why MLS square footage is often wrong

Listing agents enter square footage into the MLS manually. In most markets, there is no independent verification requirement. Agents typically use one of these sources:

Prior listing data — copying the figure from a previous sale. Errors propagate forward indefinitely this way.
County assessor record — often outdated, especially for homes with additions or renovations that were not re-assessed.
Builder marketing materials — which frequently overstateANSI-compliant gross living area by including garages, unfinished space, or rooms with sloped ceilings below the counting threshold.
Owner estimate — sellers sometimes provide a figure from memory or from marketing materials they received when they bought the home.

Because there is no systematic check against physical measurement, inaccurate figures can persist in the MLS for decades. Redfin displays what it receives.

How far off can Redfin square footage be?

Studies of MLS accuracy consistently find significant error rates. A meaningful share of listings have square footage figures that are off by more than 5%, and errors of 10% or more are common enough that buyers and appraisers routinely encounter them. For a 2,000 square foot home, 10% is 200 square feet, a difference that materially affects price per square foot comparisons and appraisal outcomes.

The direction of error matters too. Redfin's square footage figures, like all portal figures, tend to be:

Overstated for older homes where the assessor record predates additions, or where the listing agent copied an inflated figure from an earlier listing.
Overstated for new construction where builder figures include space that does not count toward above-grade GLA under appraisal standards.
Inconsistent for condos, where some sources report interior square footage and others report total square footage including balconies or storage unit allocations.
Understated for homes with unreported additions where the assessor record was never updated.

Is Redfin more accurate than Zillow?

In active listing markets, Redfin often has better data freshness because of its direct MLS brokerage relationships. But for square footage specifically, freshness is not the limiting factor. The MLS figure itself is the problem, and Redfin cannot fix upstream errors in what listing agents enter.

For off-market homes, both portals are drawing from similar county assessor and tax record sources, so accuracy is comparable. For active listings, Redfin may show the current MLS figure more reliably than Zillow in some markets, but the question is whether that figure is correct to begin with.

Neither Redfin nor Zillow measures homes. They display what they receive. The only way to get an accurate figure is independent physical measurement. For a full walkthrough of every online source and how reliable each one is, see how to find a home's square footage online.

When Redfin square footage disagreements become a problem

At the appraisal

If you make an offer based on a price-per-square-foot analysis that assumed Redfin's figure was correct, and the appraiser measures a materially different number, the appraisal may come in below your purchase price. Lenders base loan amounts on the appraised value. A significant square footage discrepancy can create a financing gap on a deal you've already committed to.

At price negotiation

If the listing overstates square footage and you catch it before making an offer, you have a legitimate basis for negotiation. If you catch it after going under contract, you can raise it as a material disclosure issue depending on your state's square footage disclosure laws.

For comparable sales analysis

Price-per-square-foot comparisons only work if all homes are measured the same way. Redfin's automated estimates (the Redfin Estimate, its equivalent of the Zestimate) use the square footage in its database as an input. If that figure is wrong, the valuation model starts from a wrong premise. This is worth remembering when using Redfin's comparative market analysis tools.

How to verify square footage when using Redfin

Check if a floor plan is attached to the listing

Redfin increasingly includes floor plan images in listing details, particularly for homes where the seller's agent used a professional floor plan service. If a floor plan is available and it appears to be to scale, you can calculate the square footage yourself and compare it to the Redfin figure before making an offer.

Upload the floor plan to PlanSnapper, trace the exterior perimeter, and set one known reference dimension. The result gives you an independently calculated figure using the same methodology appraisers use, before you commit to a price.

Cross-reference with county assessor records

Most county assessors publish parcel data online. Look up the property by address or parcel number and compare the assessor's square footage to what Redfin shows. If they match, both are drawing from the same source. If they disagree, investigate which is more recent and which is more likely to reflect physical measurement.

Ask for the appraisal sketch from a prior sale

If the home sold within the last decade and was financed, there is almost certainly an appraisal sketch on file that includes exterior dimensions. Sellers are not obligated to share it, but many will. If available, an appraisal sketch is more reliable than either Redfin's figure or the assessor record because it was produced from actual exterior measurement.

Don't take the listing's word for it

If the listing has a floor plan, verify the square footage before you bid. Upload it to PlanSnapper, trace the perimeter, get your own number in under 2 minutes.

Get access →

What Redfin discloses about its square footage data

Redfin's listing pages typically include a small disclaimer noting that square footage figures come from the seller or public records and have not been verified. This is standard across real estate portals and is legally protective for Redfin, not a guarantee of accuracy for buyers.

The disclaimer matters because it shifts responsibility. If you rely on Redfin's stated square footage in your offer and it turns out to be significantly wrong, Redfin's legal exposure is limited by that disclosure. The risk is yours.

The bottom line

Redfin is a well-designed tool for searching listings and understanding market trends. Its square footage figures are not reliable enough to use as a primary input for pricing decisions, appraisal planning, or any transaction where accuracy matters. Treat portal figures as a starting point and verify independently when the stakes are high.

The fastest verification path: check if the listing has a to-scale floor plan, then calculate the square footage yourself before the appraisal does it for you.

Related Resources

Frequently Asked Questions

How far off can Redfin square footage be?

Studies of MLS accuracy consistently find significant error rates. A meaningful share of listings have square footage figures that are off by more than 5%, and errors of 10% or more are common. For a 2,000 square foot home, 10% is 200 square feet -- a difference that materially affects price-per-square-foot comparisons and appraisal outcomes.

Is Redfin more accurate than Zillow for square footage?

In active listing markets, Redfin often has better data freshness because of its direct MLS brokerage relationships. But for square footage specifically, freshness is not the limiting factor -- the MLS figure itself is the problem. Neither Redfin nor Zillow measures homes. They display what they receive. The only way to get an accurate figure is independent physical measurement.

What should I do if Redfin shows the wrong square footage for my home?

Redfin pulls square footage from the MLS and public records. To fix it durably, start with your county assessor -- if the assessor record is wrong, Redfin will keep reverting. Once the assessor record is corrected, contact the listing agent or your MLS to update the active or past listing. Redfin will typically sync the new figure on its next data refresh. For a pending dispute, you can also submit a correction through Redfin's homeowner tools, but this is a temporary override.

Does Redfin square footage include the basement?

Redfin displays whatever square footage is in the MLS or county assessor record. If the listing agent included finished basement square footage in the total, Redfin will show that combined figure. If the assessor only counted above-grade space, Redfin reflects that instead. There is no consistent standard across listings, which is why verification is essential.

Why does Redfin show different square footage than the county assessor?

Redfin uses MLS data for active listings and county assessor records for off-market homes. These two sources often disagree. The MLS figure may include a finished basement or recent addition not yet reflected in assessor records, or an agent may have entered a different figure than what the assessor has on file. Neither source requires physical verification.

Can I correct the square footage listed on Redfin?

Homeowners can submit a correction through Redfin's homeowner dashboard, but this is a temporary override. For a durable fix, the underlying data source needs to be updated. If the error originates in the county assessor's records, contact the assessor's office. If it comes from an MLS listing, contact the listing agent or your MLS to correct the figure.

How does wrong square footage on Redfin affect home value estimates?

Redfin's home value model uses the square footage in its database as one input. If that number is wrong, the model starts from an inaccurate baseline. A home with overstated square footage will show a higher Redfin Estimate than its actual value supports, while an understated figure will produce a lower estimate. Always cross-check automated estimates against an independent measurement.

Verify square footage from any floor plan

Upload a floor plan, set the scale, and trace the perimeter. Get an accurate square footage figure you can use to verify, dispute, or document. No install required.

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