Zillapi and RentCast both return property data by address, and the practical difference is whose valuation you get. Zillapi returns Zillow-sourced data including the Zestimate, price history, photos and schools. RentCast returns its own independent AVM for value and rent, plus active sale and rental listings and market trend data across all 50 states. If your users expect to see the Zestimate specifically, use Zillapi. If you want an independent valuation model, rental analytics, or commercial property coverage, RentCast is the better fit.
Zillapi is an independent service and is not affiliated with, endorsed by, or connected to Zillow Group, Inc. or RentCast. Zillow and Zestimate are trademarks of their respective owners, used here only to describe the data our API returns.
At a glance
| Zillapi | RentCast | |
|---|---|---|
| Valuation | Zestimate and rent Zestimate, Zillow-sourced | Own AVM for value and rent, with estimate range |
| Coverage claim | 160M+ US residential | 150M+ US property records, residential and commercial |
| Listings | Property records and price history | Active for-sale and for-rent listings, all 50 states |
| Market data | Per-property | Per-property plus market trend endpoints |
| Lookup by address | Yes, one REST call | Yes |
| Billing | Credits, one per successful call | See their pricing |
| Free tier | 100 credits at signup, no card | Free tier available |
What is the RentCast API?
RentCast is a property data API that returns its own valuation estimates, active listings and market trends for US residential and commercial properties. Its own materials describe 150M+ property records, an AVM for both value and rent with a confidence range, comparable properties, and for-sale and for-rent listings across all 50 states.
That AVM is the thing to understand about RentCast: the valuation is theirs. It is computed from property characteristics and nearby comparable listings, independent of any consumer-facing estimate your users may already recognise.
What does Zillapi do differently?
Zillapi returns Zillow-sourced property data, which means the Zestimate rather than an independent model. For a product whose users already know and ask for “the Zestimate,” that is not a preference, it is a requirement, because a different number with a different name will read as wrong however good the model behind it is.
One call by street address returns the Zestimate and its range, rent Zestimate, full price history, tax assessment, beds, baths, square footage, schools, photos and comparable sales.
curl -G https://api.zillapi.com/v1/properties/by-address \ --data-urlencode "address=1600 Pennsylvania Ave NW, Washington DC 20500" \ -H "Authorization: Bearer $ZILLAPI_KEY"Response fields follow the published OpenAPI spec; look up by identifier with /v1/properties/{zpid} and fetch the valuation alone with /v1/properties/{zpid}/zestimate.
Working specifically with Zillow property data? Start with our Zillow API guide.
Which one should you choose?
Choose on what your product has to show, not on feature counts. RentCast is the better choice if you need an independent AVM, rental market analytics, commercial property coverage, or active listing search. Zillapi is the better choice if you need Zillow-sourced records and the Zestimate by name, with price history, photos and schools in the same response.
Neither answer is close when you frame it this way, which is why the framing matters more than a feature table.
Can you use both?
Yes, and for some products that is the correct answer rather than a hedge. Use RentCast for rental analytics and market trends, and Zillapi where a user expects to see the Zestimate for a specific home. They answer different questions about the same address, and both accept a free-form US address as input, so the integration shapes are similar.
How do you get property data by address?
Send the address to a single endpoint and read structured JSON back. With Zillapi that is /v1/properties/by-address with a free-form US address, which we geocode and resolve internally, so you do not need an identifier before you start. This is the most common integration pattern we see: a list of addresses in, enriched property records out.
You can try it on the free tier. Create an account, read the quickstart, and see current plans on the pricing page.
If you are also evaluating public-records providers, see Zillapi vs ATTOM Data and our ATTOM API guide.
Zillapi is an independent service and is not affiliated with, endorsed by, or sponsored by Zillow Group, Inc. “Zillow” and “Zestimate” are registered trademarks of Zillow Group, Inc. Use of those marks on this site is descriptive (nominative fair use). Read our full trademark posture.