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Zillow vs Trulia Square Footage: Why the Numbers Are Different
You search the same address on Zillow and Trulia and get different square footage numbers. It happens constantly. Here is exactly why it happens, which number to trust, and what the square footage figure on any listing site actually represents.
The quick answer
Zillow and Trulia are the same company -- Trulia was acquired by Zillow in 2015. Despite this, they sometimes display different square footage for the same property because they pull data from different sources and update on different schedules.
Neither number is necessarily accurate. Both are pulling from third-party data -- county tax records, MLS listings, and user-submitted corrections -- and that data is inconsistent by nature.
Where Zillow and Trulia get their square footage
| Source | What it is | Accuracy |
|---|---|---|
| County tax records | Assessor's measurement, often from original permit | Frequently outdated; may exclude additions |
| MLS listing data | Agent-entered at time of listing | Varies widely; often includes basement in some markets |
| Public records | Compiled from assessor and deed records | Same issues as county records, just aggregated |
| Owner/agent corrections | Submitted via Zillow's edit interface | Unverified; can be inflated |
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- Different data pulls. Even though Zillow owns Trulia, the two sites have historically maintained separate data pipelines. A correction made on Zillow may not propagate to Trulia immediately -- or ever.
- Different MLS feeds. Zillow and Trulia may receive slightly different MLS data depending on the feed configuration in each market. Agents control what gets entered, and errors carry forward.
- Update timing. County records updates, listing changes, and data corrections do not sync between platforms in real time. One site may be showing a listing from 2019 while the other has the 2024 version.
- Definition inconsistency. "Square footage" means different things to different people. Some MLS systems include finished basement area. Others follow ANSI Z765, which excludes below-grade space from GLA. Zillow and Trulia display whatever number they receive without standardizing the methodology.
Which number should you trust?
Neither, without verification. Listing site square footage is directionally useful -- it tells you roughly what size category a property falls in -- but it is not reliable enough to base a purchase decision on.
For the most reliable square footage figures, in order of reliability:
- Licensed appraisal report -- the gold standard. An appraiser measures the property following ANSI Z765 standards and provides a documented GLA figure. This is what lenders rely on.
- County assessor record -- better than listing sites, but may reflect the original permitted structure and miss additions or renovations done without permits.
- MLS listing at time of sale -- more current than county records in active markets, but reflects what the listing agent entered (which may follow inconsistent methodology).
- Zillow / Trulia -- useful for ballpark comparisons, not for precise measurements.
The basement problem
The biggest source of discrepancy between listing sites and appraisals is basement area. Under ANSI Z765 (the standard residential appraisers follow), below-grade space never counts as Gross Living Area (GLA), regardless of how finished it is.
Many listing agents include finished basement square footage in the total. A house with 1,600 sq ft above grade and 800 sq ft of finished basement might be listed at 2,400 sq ft on Zillow, while the appraisal report shows 1,600 sq ft GLA. Both numbers can be accurate -- they are measuring different things. See our guide on above-grade vs below-grade square footage for a full explanation.
What to do if the numbers do not match
- Pull the county assessor record. Most counties have a free public portal. The assessor's figure is usually the baseline.
- Request an appraisal. If the discrepancy is significant or you are making a purchase decision, a licensed appraiser's measurement is the only figure that carries professional accountability.
- Check the listing agent's methodology. Ask whether the stated square footage includes basement, unfinished space, or additions. Most will tell you.
- Verify with a floor plan. If a floor plan is available, you can upload it to a tool like PlanSnapper, trace the perimeter, and calculate the above-grade GLA yourself in a few minutes.
The bottom line
Zillow and Trulia show different square footage because they are pulling from inconsistent sources and updating on different schedules -- not because one is intentionally more accurate than the other. For any property where the number matters, do not rely on either. Pull the assessor record, request a floor plan, or get an appraisal.
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Get StartedRelated reading
- Deed square footage vs appraisal: which is accurate?
- How to measure the square footage of a house
- What is gross living area (GLA)?
- Floor plan measurement tool for GLA calculation
- Zillow vs Redfin Square Footage Accuracy: comparison
- Is Zillow square footage accurate?: FAQ
- Appraisal square footage vs. listing square footage: FAQ
Frequently Asked Questions
What is the difference between Zillow and Trulia Square Footage?
Zillow and Trulia Square Footage are different tools with different strengths. The best choice depends on your workflow, budget, and whether you need features like 3D scanning, floor plan generation, GLA calculation, or design capabilities. This page breaks down a direct comparison.
Which is better for real estate appraisers: Zillow or Trulia Square Footage?
Zillow and Trulia Square Footage serve different workflows. Zillow is better suited for one use case while Trulia Square Footage fits another: the right choice depends on whether you need field capture or office-based GLA calculation from existing floor plans.
Can Zillow and Trulia Square Footage be used together?
Zillow and Trulia Square Footage can complement each other in some workflows: for example, using one for field capture and the other for GLA calculation and reporting. Check the comparison table above for specific integration details.
How much does Zillow cost compared to Trulia Square Footage?
Zillow and Trulia Square Footage have different pricing models: one may charge per user, per project, or via annual subscription, while the other may offer a free tier or pay-per-use option. Check the comparison table above for current pricing details and which offers better value for your volume of work.
Which is easier to use: Zillow or Trulia Square Footage?
Ease of use depends on your starting point. Zillow tends to fit one type of user or workflow, while Trulia Square Footage is designed for another. If you are working from an existing floor plan PDF and need to calculate square footage quickly, a browser-based tool like PlanSnapper may reduce the learning curve entirely: no software installation required.
Do I need Zillow or Trulia Square Footage if I already have a floor plan PDF?
If you already have a floor plan as a PDF or image, you may not need either tool. PlanSnapper lets you upload the PDF directly and trace walls in your browser to calculate GLA: no software installation required. Both Zillow and Trulia Square Footage are most useful for creating sketches from scratch or capturing measurements in the field.
Which works better for calculating GLA: Zillow or Trulia Square Footage?
Both Zillow and Trulia Square Footage can support GLA calculation, but the workflow differs. One may require field measurement and sketch entry while the other may allow importing existing floor plans. If your starting point is an existing PDF or image floor plan, PlanSnapper provides a faster path: upload, trace, and get the GLA figure without entering either tool's workflow.
How do Zillow and Trulia Square Footage handle existing floor plan PDFs?
Neither Zillow nor Trulia Square Footage is primarily designed to import and calculate square footage from an existing PDF floor plan. Both tools are built around creating or capturing floor plans from scratch. If you already have a PDF floor plan, PlanSnapper lets you upload it directly, trace the walls, and get an accurate GLA figure without redrawing anything.
Which is better for occasional users: Zillow or Trulia Square Footage?
Zillow and Trulia Square Footage are both specialized tools with learning curves that reward regular use. Occasional users often find dedicated subscription tools hard to justify. For someone who needs to calculate square footage a few times a month, PlanSnapper is designed for exactly that: no training required, no annual contract, upload and measure in minutes.