Property analysis built from public records, not guesswork
Comp-supported valuation, tax projection, school ratings, flood risk, condition assessment, and a blunt honest opinion — for any Illinois or Michigan residential property, in under two minutes.
Analyze a property →No account needed to run an address and see the summary.
Comp-supported valuation
A defensible price range built from actual comparable sales in the area — not a single black-box number.
Post-sale tax projection
What your property tax bill actually becomes after a purchase closes — Cook County's real reassessment timeline in Illinois, Proposal A's assessment-uncapping rule in Michigan.
Condition & flip detection
Permit history, assessor records, and price history cross-checked to flag flips, unpermitted work, and overpricing.
An honest opinion
Every report ends with a blunt, plain-English verdict — not a sales pitch, and not a recommendation to buy or not buy.
How it works
Enter an address
We resolve it to a real parcel, then pull assessor records, sales history, permits, school ratings, and flood data. A free summary and an honest read come back before you commit to anything.
Confirm what we can't see
Public records don't know the asking price or whether the kitchen was redone last year. Answer as few or as many optional questions as you like — each one narrows the range and raises the confidence label.
Get the full report
About 90 seconds later you have the complete analysis — comps, tax scenarios, condition assessment, due-diligence checklist. Download it as a PDF or ask follow-up questions about it.
See a real report
This is an actual published summary — valuation range, condition read, current and projected tax, school ratings, the confidence label, and what would tighten the analysis. Nothing staged.
6531 S Drexel Ave, Chicago
Cook County — the deepest data coverage, including the public comp engine, assessor condition rating, permit history, and per-school profiles.
View the sample report →What’s in a full report
Around nineteen sections, adapted to the property and to whether you’re buying, selling, or evaluating it as an investment.
Valuation
- Comparable sales with $/sqft normalization
- Price positioning vs. the comp range
- Price history and prior-sale context
- Flip detection and implied renovation margin
Money
- Post-sale tax projection across four scenarios
- Cash to close and monthly carrying cost
- Rent estimate, gross yield, and cap-rate proxy
- Financing scenarios at current benchmark rates
Condition & risk
- Condition tier from assessor and permit evidence
- Public records vs. listing discrepancies
- Flood zone, environmental hazards, transit
- Schools, and a due-diligence checklist to work from
Where the data comes from
Reports are built from government and public records, with licensed market data filling the gaps public sources don’t reach. Every figure carries its provenance, and a gap is reported as a gap rather than filled with a guess.
Cook County & City of Chicago open data
Parcel records, assessor characteristics and condition ratings, arm's-length sales, building permits, code violations, and per-school CPS profiles.
Illinois Department of Revenue
MyDec transfer declarations for statewide arm's-length sale records, plus the annual county equalization factors.
Illinois State Board of Education
The 2025 Report Card — proficiency, graduation rates, absenteeism, and per-pupil spending for all 864 Illinois districts.
BS&A Online (Michigan)
Per-parcel State Equalized Value, Taxable Value, and sale history for Michigan municipalities where the record is public — the basis for a real post-sale Proposal A tax projection, not a rate-table guess.
U.S. Census Bureau
TIGERweb school-district boundaries resolved by point-in-polygon, and American Community Survey neighborhood data.
FEMA
National Flood Hazard Layer flood zone and special-flood-hazard-area determination.
HUD
Small Area Fair Market Rents behind the rent model, plus affordable-housing and inspection-score datasets.
Federal Reserve (FRED)
Mortgage benchmark rates, the Case-Shiller price index, and county-level market trend data.
Common questions
What does it cost to try?
Running an address and seeing the summary and honest opinion costs nothing, and doesn't require an account or a card. Signing in is only needed to save an analysis, compare properties, or ask follow-up questions.
How accurate is the valuation?
It's a probabilistic range, not an appraisal, and every report carries a first-class Analysis Confidence label that tells you how much weight it deserves. A thin comp pool or an undetermined condition gets labeled Low — we'd rather say the analysis is weak than quietly hand you a confident-looking number built on two sales.
Which areas are covered?
All 102 Illinois counties, plus Michigan. Depth varies: Cook County properties get the fullest treatment, since the county publishes parcel, assessor, sales, permit, and violation data we can build a comp engine directly on top of. Other Illinois counties draw on statewide and federal sources plus licensed market data. Michigan is newer and intentionally leaner today — real per-parcel tax and assessment data where a municipality's own records are public, plus federal sources and licensed market data, but not yet the statewide school-ratings or tax-rate depth Illinois has. A report always says plainly when a section is thinner because the data isn't there yet, rather than filling the gap with a guess.
Will it tell me whether to buy?
No, and that's deliberate. Reports never recommend buying or passing. They lay out what the data supports, flag what's uncertain, and name the risks worth verifying — the decision stays yours.
Is this an appraisal or a broker's opinion?
Neither. CompBasis is not a licensed real estate broker, salesperson, or appraiser, and a report is not an appraisal, a comparative market analysis prepared by a licensee, or a substitute for a home inspection. It's research to inform your own judgment.
What if something in a report looks wrong?
Every report has a button to flag it. Public records genuinely do contain errors — mis-recorded square footage, stale property classifications, missing permits — and reports say when a figure looks inconsistent rather than papering over it.
Read up first
Run an address
Covers all 102 Illinois counties, plus Michigan. Built for buyers, sellers, and investors researching a property. Never recommends buy or don't buy — the analysis is yours to act on.
Analyze a property →