Methodology

How we estimate over-assessment

The Free tier runs the same five-step analysis on every Dallas County address you enter:

1. Scrape current DCAD parcel data. The Dallas Central Appraisal District publishes assessed values, year built, building square footage, and parcel geometry on maps.dcad.org/.../ParcelQuery. We mirror that public dataset on roughly a quarterly cadence.
2. Run a PostGIS spatial query. When you submit your address, we look up the closest comparable residential properties by physical distance using the parcel centroids stored in our PostGIS index.
3. Take the median of the 10 closest comps.The median assessed value of those neighbors becomes our estimated fair value for your property — robust against outliers and DCAD’s mass-appraisal noise.
4. Compute the over-assessment delta. Your assessed value minus the comp-derived fair value is the estimated over-assessment.
5. Apply the local tax rate. We multiply the delta by the Dallas County effective rate (roughly 2.1% as of writing) to get an estimated annual savings figure.

Estimate, not guaranteed. Our number is a starting point for your own protest research, not a prediction of the outcome. Every Dallas County protest is decided by the appraisal review board (ARB) on the specific evidence the homeowner presents.

The proof-point stats

Two stats appear on our homepage and we want to be transparent about where they come from.

“30–60% of Dallas homes appear over-assessed”

Methodology:Based on our analysis of N Dallas County residential parcels actively scraped from DCAD’s public records (last refreshed: 2026-05-02), X% showed an assessed value at least Y% above the comp-derived fair value of similar properties within 1 mile, similar size, and similar year built.

Methodology calculation in progress; the exact N / X / Y numbers will be finalized after the first full quarterly DCAD refresh completes. The 30–60% range is an informed estimate based on our current development-corpus sample, not a published study.

“$800–$2,400 typical annual savings”

Methodology:Among Dallas County homeowners who successfully protest a residential assessment, a typical annual property-tax reduction falls in the $800–$2,400 range. This range is intentionally wide and is a typical-outcome figure, not a prediction for your specific property.

Your actual savings will depend on (a) how much your assessment is above comp-derived fair value, (b) the evidence you present at protest, and (c) the appraisal review board’s decision. We do not file your protest for you; we provide an estimate and a deadline reminder.

Source data

Public DCAD parcel data accessed via maps.dcad.org/.../ParcelQuery. No private MLS, no Zillow, no third-party valuation models. Only public records + a PostGIS spatial query.

What the AI does

On every successful lookup, we use Google’s Gemini 2.5 Flash (via OpenRouter) to generate a 2–3 sentence narrative explaining your specific over-assessment in friendly, plain English. The AI receives your assessed value, the comp-derived fair value, and the savings delta — nothing else — and writes the explanation.

The AI does not decide whether you should protest, what to file, or what evidence to present. Those choices are yours. Filing a Dallas County protest yourself takes about 10 minutes at dallascad.org.

What we do NOT do

• Provide legal advice.
• File protests on your behalf. (An AI Agent that does this is a planned future tier — not yet shipped.)
• Represent you before the appraisal review board.
• Guarantee any specific savings outcome.