Buyer's Guide · Real Estate Data APIs · 2026
PropData
vs
ATTOM
vs
RentCast
vs
Cotality (CoreLogic)
Every other property database decays. This one compounds.
Licensed data is a photograph — accurate the day it's taken, a little less accurate every day after. PropData is a pipeline: 166M+ parcels ingested directly from county assessor and GIS systems, refreshed nightly, scored field by field, and made denser by every search that runs through it.
OUR PLATFORM
PropData
// Own pipeline · nightly refresh
$79/mo
Starter · 10,000 requests · 20+ routes
For developers, operators, and AI teams that want parcel, market, rent, risk, and geospatial workflows in one platform — with a database that gets denser every night.
RentCast
// Self-serve property + rental API
$74/mo
Foundation · 1,000 requests · overages
For teams that want a polished self-serve API for property records, AVMs, comps, listings, and market trends.
ATTOM Data
// Enterprise property data platform
Custom quote
API · bulk · cloud · MCP
For organizations needing deep deed, mortgage, foreclosure, and bulk-delivery workflows under an enterprise contract.
Cotality
// Formerly CoreLogic
Custom quote
product-specific enterprise pricing
For lenders, insurers, government, and valuation teams buying regulated institutional data programs.
SECTION 01 · TL;DR
The 30-second answer.
Price is the least interesting difference between these platforms, and it's the last thing you should evaluate us on. The interesting difference is structural, and it shows up the first time you query an address that isn't in the extract.
The large vendors license public county assessor records, normalize them in an ETL pipeline, and sell you the output on a contracted refresh schedule. It's a legitimate business, and for some workflows it's the correct purchase. But it produces two properties every one of their customers eventually feels: the dataset is a snapshot, and a miss is permanent. Query an address that isn't in the extract and you get a null. Query it again next month and you get the same null. Nothing about your search made the system better.
PropData was built on the opposite assumption: the database should be denser tomorrow because of what you asked it today. We own the ingest, so it runs nightly. We score every field, so you know what's verified rather than discovering gaps in production. And when a property isn't there yet, the API doesn't shrug — it goes and gets it from the county, scores it, caches it, and keeps it.
Every other provider returns null on a miss. PropData treats the miss as the most valuable signal the API receives — a developer just told us exactly which gap matters.
// The Miss Flywheel
Here's the short version of the field, in the order most builders should think about it:
- PropData — $79/month for 10,000 requests. 166M+ parcels from an owned county ingest pipeline, refreshed nightly, with field-level confidence scoring, self-enriching miss handling, FEMA hazard and flood layers, safety and Opportunity Zone data, comps, geocoding, coordinate-to-parcel matching, parcel geometry, delta feeds, skip trace, pre-foreclosure, and MCP access across 20+ endpoint routes.
- RentCast — 50 free monthly requests, then $74/month for 1,000. A mature self-serve API covering property records, owners, tax data, AVMs, sales and rental comps, active listings, and market trends. Genuinely good at what it does.
- ATTOM — 160M+ properties with deep tax, deed, mortgage, foreclosure, hazard, and neighborhood products across API, bulk, cloud, and MCP delivery. Production pricing is quote-based.
- Cotality (formerly CoreLogic) — the institutional platform. 5.5B property records spanning 50 years, specialized valuation and risk products, cloud delivery, and an MCP server. Pricing is product-specific and quote-based.
SECTION 02 · ARCHITECTURE
Two ways to build a property database.
Both models start in the same place: a county government publishing public assessor and GIS records. What happens next is the entire difference.
Licensed and resold
// the standard model
- County publishes public records
- Vendor licenses or extracts the data
- ETL normalization, vendor-side
- Snapshot ships on a contracted cadence
- You query the snapshot
- Miss returns null — permanently
Accuracy peaks on ingest day.
Owned pipeline
// PropData
- County publishes public records
- We hit the county ArcGIS layer directly
- Our ingest workers normalize and upsert
- Nightly refresh, per-source crons
- You query Supabase through the edge
- Miss fires enrichment — coverage kept
Accuracy compounds with usage.
// WHY "NO MIDDLEMAN" IS A TECHNICAL CLAIM, NOT A SLOGAN
Every layer between the county record and your response is a place where a value can be transformed, dropped, or delayed. Owning the ingest means that when a county renames a field, republishes a layer, or corrects a bad parcel, we can chase it that night — instead of filing a ticket with an upstream vendor and waiting for their next release. It also means no third-party redistribution terms sitting on top of whatever you build.
What that buys you in practice
- Nightly parcel refresh, with source-specific crons for market layers — HUD weekly, ZORI and Realtor monthly, FRED weekly.
- Field-level confidence scoring so parcel ID, market value, annual tax, year built, property type, and lot size each carry their own source attribution instead of arriving as one undifferentiated record.
- Coverage metadata exposed through the API via
/v1/property/coverage, so you can see what's verified for a county before you ship — not when a customer finds the gap.
- Direct source expansion. If your county isn't covered the way you need, that's a pipeline we can extend — not a licensing negotiation with a third party.
SECTION 03 · THE MISS FLYWHEEL
The only property database that learns from what it can't answer.
Every other provider treats a missing property as an error state. We treat it as the most valuable signal the API receives.
Miss detected
The property isn't in the production database yet. Instead of returning a null and forgetting it happened, the pipeline fires immediately.
Source-backed lookup
A live query runs against permitted government data — county ArcGIS assessor layers and verified public records only. Nothing is generated, inferred from a model, or filled in from a third-party aggregator.
Field-level confidence scoring
Parcel ID, market value, annual tax, year built, property type, lot size — each derived deterministically and scored individually. You're told which fields are solid, not handed one record and left to guess.
Edge storage and review queue
Written to Supabase and Cloudflare KV, queued for promotion. The repeat lookup returns in under a second from learned cache.
Coverage compounds
The gap closes for everyone. The next developer who queries that address gets a hit. Multiply that across every search running through the platform and the database gets denser every day it stays online.
// THE HONEST VERSION OF THIS CLAIM
Enrichment is bounded by what a county actually publishes. If a county doesn't put bedroom counts in its public layer, no pipeline on earth conjures them — and any vendor promising otherwise is selling you a model output labeled as a record.
What the flywheel guarantees is different and more useful: a miss becomes a documented, source-attributed attempt with scored fields — and wherever the county publishes it, you keep it permanently.
SECTION 04 · SCOPE
Included, not add-on.
Enterprise property platforms tend to sell risk, geospatial, lead, and scoring layers as individually contracted products. These ship inside published PropData tiers.
FEMA National Risk Index
18 natural hazard scores by county — wildfire, flood, hurricane, tornado, earthquake, heat, drought and more — as per-capita annualized loss percentiles, so you aren't comparing Maricopa to rural Kansas unfairly.
/v1/neighborhood
FEMA flood hazard zone
National Flood Hazard Layer zone per property — A, AE, X — so mandatory-insurance exposure is visible at the parcel, not the county.
/v1/property?enrich=full
Community safety score
Composite A–F grade built from NCES school data across 100K+ schools, Census ACS poverty and unemployment, social vulnerability, and crime signals.
/v1/neighborhood
Opportunity Zone + USDA flags
Every ZIP flagged for federal OZ designation and USDA rural loan eligibility. Two filters that change deal structure before underwriting starts.
/v1/zip-intel
Parcel geometry + coordinate match
GeoJSON boundary, centroid, and bbox where county GIS coverage is configured — plus point-in-polygon lookup for when a geocoded pin disagrees with the situs address.
/v1/parcel-geometry · /v1/property/by-location
Comparable sales engine
Ranked comps scored on price, square footage, recency, and bedroom count — computed against the owned parcel database rather than licensed from a third party.
/v1/comps
Delta feeds
Changed property and pre-foreclosure records since any timestamp, with cursor pagination — so you sync what moved instead of re-pulling the world.
/v1/property/delta · /v1/preforeclosure/delta
Computed investor flags
Equity estimation, absentee-owner detection (mailing ZIP ≠ situs ZIP), and vacant-land flags derived at query time instead of sold as an analytics upgrade.
/v1/property
AI-native access
An OAuth-protected MCP connector lets supported ChatGPT and Claude workflows call live PropData tools with a subscriber's own key. A public changelog endpoint makes updates programmatically trackable.
/v1/changelog · propdata-mcp
// PROVENANCE RULE
PropData's parcel layer is built from government public records — county assessor and GIS systems, Census, HUD, HMDA, FEMA, FHFA and FRED — with clearly labeled market layers from published research sources. Provenance is stated per response through source attribution, because a data layer you can't explain to a compliance reviewer is a data layer you can't ship in a regulated workflow.
SECTION 06 · COST
What you'll actually pay.
Pricing pages are nice. Real cost is what shows up on your invoice at production volume. Only PropData and RentCast publish directly comparable self-serve tiers — ATTOM and Cotality require product- and volume-specific quotes, so this page shows them as unknown rather than inventing a number.
ATTOM
NOT PUBLISHED — QUOTE REQUIRED
?
Cotality
NOT PUBLISHED — QUOTE REQUIRED
?
ATTOM
NOT PUBLISHED — QUOTE REQUIRED
?
Cotality
NOT PUBLISHED — QUOTE REQUIRED
?
ATTOM
NOT PUBLISHED — QUOTE REQUIRED
?
Cotality
NOT PUBLISHED — QUOTE REQUIRED
?
These are price comparisons, not claims of identical data. RentCast includes property-level AVMs, comps, and active listings that may be the deciding factor for your product. Compare response quality on your actual markets before choosing — and note that the meaningful difference above isn't the dollar figure, it's that the same PropData plan absorbs a 10× volume increase without an overage line.
SECTION 07 · WHO USES WHAT
Which one to actually pick.
Forget feature checkboxes for a second. Here's the actual decision tree.
// PICK PROPDATA IF
You want a data layer that improves while you're using it.
Choose PropData when your workflow combines parcel resolution, assessor and GIS fields, rent and market signals, government risk layers, coordinate-to-parcel matching, geometry, and MCP access — and when you'd rather have coverage gaps close on demand than sit behind a licensing negotiation.
Examples: investor screeners · AI property agents · market dashboards · map-click workflows · underwriting tools · custom county integrations
// PICK RENTCAST IF
You want polished self-serve property, AVM, comp, and listing endpoints.
RentCast is compelling when property-level rent and value estimates, nearby sales and rental comps, active listings, and owner/tax records are central to the product. Its free 50-request tier is useful for a small proof of concept.
Examples: rent-pricing tools · landlord software · listing applications · rental comp reports
// PICK ATTOM IF
You need deed, mortgage, and foreclosure depth with bulk delivery.
ATTOM is the stronger evaluation when deeds, mortgages, foreclosure history, persistent property identity, bulk licensing, cloud delivery, or enterprise redistribution rights are central requirements. That's real capability we don't sell.
Examples: title research · mortgage analytics · enterprise data warehouses
// PICK COTALITY IF
The workflow is institutional, regulated, or model-driven.
Cotality is built for organizations whose decisions depend on specialized valuation, mortgage, insurance, climate, and imagery products with enterprise governance and decades of historical depth behind them.
Examples: mortgage underwriting · servicing · institutional valuation · catastrophe risk
SECTION 08 · QUESTIONS
What developers ask first.
What makes PropData different from ATTOM, CoreLogic, or RentCast?
Architecture. Most platforms license county assessor records, run an ETL pipeline, and resell a static snapshot — so a failed lookup returns null forever and the dataset ages between refreshes. PropData owns the ingest directly from county ArcGIS and assessor systems, refreshes nightly, scores every field for confidence, and fires a live source-backed lookup when a property is missing. That miss becomes permanent coverage for every future request.
What is the Miss Flywheel?
PropData's self-enriching pipeline. When a property isn't in the production database, the API doesn't return null — it queries permitted government sources live, derives fields deterministically, scores each one for confidence, writes to Supabase and Cloudflare KV, and queues it for promotion. The repeat lookup returns in under a second, and the coverage gap stays closed for every future caller.
How much does a property data API cost per month?
Published self-serve pricing as of July 2026: PropData is $79/month for 10,000 requests, $199 for 50,000, $499 for 250,000, and $1,499 for unlimited. RentCast is free for 50 requests, $74 for 1,000, $199 for 5,000, and $449 for 25,000 with published overages. ATTOM and Cotality don't publish universal production pricing and require a custom quote.
Do you license your parcel data from a third party?
No. Parcel records come directly from county assessor and GIS systems — the same public government source larger vendors license and resell. No aggregator sits between your call and the county record, which means no upstream licensing fees, no third-party redistribution terms on what you build, and no aggregation errors introduced by a middleman.
How often is the data refreshed?
Parcel ingest runs nightly. Market layers run on source-specific crons — HUD weekly, ZORI and Realtor monthly, FRED weekly. Enterprise vendors generally don't publish a single universal cadence because it varies by product and contract, so ask any provider for their per-dataset refresh schedule in writing. Refresh frequency is where stale-data complaints originate.
Can I look up a parcel by latitude and longitude?
Yes. /v1/property/by-location resolves the county FIPS from a coordinate, queries a verified county parcel GIS source, and returns the parcel containing the point. Successful spatial matches return match_level=point_in_polygon. It's built for map-based platforms where a geocoded pin disagrees with the legal situs address.
Does 166 million parcels mean every field is populated?
No, and no provider in this category can honestly claim otherwise — assessor depth varies because counties publish different fields. What differs is the behavior on a gap: PropData exposes coverage metadata, scores confidence per field, and runs enrichment instead of returning a silent null. Test your specific counties before committing any provider to production.
Can AI agents call PropData directly?
Yes. An OAuth-protected MCP connector lets supported ChatGPT and Claude workflows call live PropData tools — property lookup, market data, rent estimates, comps, neighborhood, parcel geometry, coordinate lookup — using the subscriber's own API key. The public /v1/changelog endpoint also makes platform updates programmatically trackable.
SECTION 09 · METHODOLOGY
How we verified the comparison.
This page is published by PropTechUSA.ai, the company behind PropData, so it is not independent editorial coverage. The way to make it useful is to separate published facts from our product opinion and link directly to each vendor's current material.
// VERIFICATION RULES · JULY 23, 2026
Public prices are shown only when the vendor currently publishes them. "Custom quote" means exactly that — we did not infer a contract value from old case studies, reseller pages, or anonymous reports, and we don't render a bar chart implying a price we can't source. Coverage counts use each vendor's own definition, which may refer to parcels, properties, records, or population coverage and should not be treated as identical units.
Refresh cadence is stated as fact only for PropData, because it's our pipeline. For other vendors we report what they publish — and where they don't publish a universal cadence, we say so.
Primary product sources
What a table cannot tell you
National record counts do not guarantee identical field depth in every county. "Real-time" does not mean every source agency publishes continuously. An API call, returned property, report, and bulk record can also be different billing units. Before signing a contract, test the exact counties, fields, volumes, redistribution rights, and latency profile your production workflow needs.
SECTION 10 · CLOSING
The honest part.
If your workflow depends on 50-year mortgage and transaction history, title-grade deed chains, bulk or warehouse delivery, enterprise redistribution rights, or regulated valuation and catastrophe models with institutional governance behind them — buy the enterprise contract. That is real capability we don't sell, and you should hear it here rather than discover it after integration.
Everything else on this page is about the workflows where that machinery is overhead instead of value: where you need current parcel data, honest coverage metadata, risk and geospatial layers, and an API key in the next five minutes.
Our own limitation is equally worth stating: 166M+ indexed parcels does not mean identical assessor depth on every record. Owner, tax, sale, structure, geometry, rent, and comp fields vary by county because counties publish different things. The difference is that we show you that variance through confidence scoring and coverage metadata instead of hiding it behind a national headline — and when a gap is closeable, the pipeline closes it.
The right decision is the provider that returns the fields you need, in the markets you need, under licensing and pricing that fit your product. If that isn't us, we'd rather find out during evaluation than after launch.
// Justin Erickson, Founder
// RUN IT AGAINST YOUR OWN MARKETS
Don't take the architecture on faith. Query it.
Pick the counties you actually care about. Run the same addresses, parcel IDs, ZIPs, and coordinates you'd run in production, then compare match rate, field completeness, provenance, and latency. Signup is self-serve, keys issue instantly, and monthly plans cancel anytime.