Real estate APIs provide property listings, market valuations, mortgage calculations, and neighborhood data. Zillow and Realtor.com offer free tiers with strict rate limits; specialized services like ATTOM focus on property records. Check data licensing — most real estate APIs restrict commercial use or require attribution.
| API | Pricing | Auth | CORS | Health | |
|---|---|---|---|---|---|
| RapidAPI Real Estate RapidAPI Real Estate: property listings, market data, and rental estimates across US markets. | Freemium | API Key | Yes | Profile | |
| RentCast Retrieve real-time property and rental data for real estate in the United States | Freemium | API Key | No | Profile |
Start with pricing and auth: free tiers and no-auth APIs are fastest to prototype with. Then check CORS if your app calls the API from the browser, and health before you commit — a great real estate API that's been down for a week will block your launch. Each profile below shows all of these signals plus rate limits where documented.