Exploring the Best U.S. Property Data APIs—and Their Drawbacks

With real estate more data-driven than ever, a solid property data API can make or break your project. Whether you’re building an investor tool, analyzing market trends, or simply automating your own property lookups, you want reliable, affordable, and up-to-date data. Below, we’ll examine leading U.S. property data APIs and note key drawbacks—often related to pricing or data limitations.

1. Realie

Why Realie Stands Out

• Cheaper Plans & Free Tier: Realie offers significantly more affordable pricing than most alternatives, plus a free tier for those who want to test or handle smaller data volumes.

• High-Volume Returns per Call: Each call can return up to 500 parcels, saving on extra fees and reducing development complexities.

• Modern UI & Easy Integration: Built with a modern, intuitive interface that makes data easy to interpret and integrate.

• Direct County Data: Data is collected straight from counties, helping ensure accuracy and timeliness.

2. ATTOM Data Solutions

Key Features

• Comprehensive nationwide coverage of tax, deed, mortgage, and foreclosure records.

• Neighborhood insights (demographics, crime, schools).

• AVM (automated valuation) estimates and analytics.

Pricing Drawback

ATTOM is enterprise-oriented, and its pricing often reflects that. While it provides a massive dataset, smaller businesses or developers may find the cost prohibitive if they need continuous, large-scale data. Negotiating a contract can also be complex and time-consuming.

3. HouseCanary

Key Features

• Automated Valuation Model (AVM).

• Rental estimates and risk analytics.

• Deep market forecasting and comparables.

Pricing Drawback

HouseCanary is known for its sophisticated analytics—particularly valued by banks and mortgage lenders. However, licensing fees and analytics packages can get expensive, especially for small businesses or lean startups looking for a budget-friendly solution.

4. RentCast

Key Features

• Rental data, including current market rent estimates.

• Historical rental listings and trends.

• Tools for rental comps and portfolio analysis.

Drawback (Data & Polygons)

• No Parcel Polygons: If you’re looking for polygon/boundary data, you’ll have to look elsewhere.

• Update Frequency: Users have noted that data updates aren’t as frequent as some competitors, potentially resulting in slightly stale or incomplete information for fast-moving markets.

5. CoreLogic

Key Features

• Large property database (assessor records, mortgages, liens).

• Advanced analytics and risk assessment solutions.

• Nationwide coverage.

Pricing Drawback

CoreLogic is a major enterprise player, and cost can be a barrier for smaller teams. Their data is top-notch, but subscription fees and per-call costs can quickly exceed budgets, and access often requires larger upfront commitments.

6. Regrid

Key Features

• Parcel boundaries and ownership details for over 150 million U.S. parcels.

• GIS-friendly data and mapping.

• Land-use and zoning info (select markets).

Pricing Drawback

Regrid offers detailed GIS data, but costs can escalate if you need extensive coverage, advanced features, or heavy usage. Some developers also find specialized GIS data to be pricier because it’s more niche, requiring robust backend systems and licensing.

7. DataTree by First American

Key Features

• County-recorded property documents, deeds, and public records.

• Historical and current ownership details.

• Nationwide coverage with premium-level detail.

Pricing Drawback

DataTree’s direct-from-county approach is extremely reliable but often comes at a premium. Contracts can be complicated for smaller entities, and bulk data pulls can become expensive if you’re not doing enterprise-level volumes.

8. Zillow API (Evolving & Limited)

Key Features (Historically)

• Zestimate” valuations.

• Comprehensive nationwide coverage of tax, deed, mortgage, and foreclosure records.

• Basic property and rental estimates (in the past).

Drawback

Zillow has significantly restricted its API in recent years. It’s no longer open to the public like it once was, making it difficult or impossible for many third parties to tap into its data. This restricted access can hamper innovative use cases

9. Mashvisor

Key Features

• Short-term rental data (including Airbnb).

• Rental income projections and ROI calculations.

• Neighborhood-level analytics.

Pricing Drawback

While Mashvisor caters well to short-term rental analytics, its subscription costs can climb if you need broader coverage or deeper historical data. The platform’s specialized focus can also mean paying for analytics you may not need if you’re working outside the Airbnb or short-term rental model.

Why Realie Might Be the Ideal Choice

1. Affordability + Free Tier
   Realie undercuts much of the market on price. The free tier makes it accessible for experimentation, demos, or smaller projects before committing to bigger usage.

2. High-Volume Returns
   Getting up to 500 parcels per call helps you do more with fewer API calls, which translates into fewer costs and simpler code.

3. Modern UI & Simple Integration
   Some legacy providers have clunky dashboards or outdated documentation. Realie’s user-friendly approach makes onboarding smoother.

4. Direct County Data
   Accuracy is paramount. By getting data directly from county sources, Realie cuts down on inconsistencies and delays found in some other solutions.

5. Scalability
   Whether you’re a startup or an established enterprise, Realie’s flexible pricing and robust infrastructure can grow with your needs.

Final Thoughts

Selecting the right property data API often comes down to the balance of quality, coverage, and cost. Established names like ATTOM, CoreLogic, and DataTree offer comprehensive data but at higher price points and more complex contracts. Meanwhile, focused platforms like HouseCanary and Regrid deliver specialized analytics or GIS data that can also get expensive for larger-scale needs.

RentCast focuses on rental data but lacks parcel polygons and can have slower updates, which may not fit certain geospatial or real-time applications. Zillow’s once-open API is no longer as widely accessible, limiting options for many developers.

If you’re seeking extensive property data with lower costs, generous free tiers, user-friendly tools, and up-to-date county records, Realie offers a compelling and modern alternative. It’s worth exploring—especially for teams looking to keep overhead low without sacrificing data accuracy or coverage.