What is MLS Data?
An MLS (Multiple Listing Service) is a centralized suite of private databases established by real estate brokers to share property listing details and co-broke commission agreements. Over 600 regional MLS boards operate across North America, powering over 90% of residential real estate transactions.
Evolution of MLS Data Protocols
1. RETS (Real Estate Transaction Standard)
RETS is an XML-based legacy HTTP protocol launched in 1999 for querying real estate databases. While RETS has been officially sunset by RESO (Real Estate Standards Organization), many legacy MLS portals still maintain RETS authentication endpoints.
2. RESO Web API (RESTful Open Data)
RESO Web API is the modern web standard, delivering normalized JSON data via standardized OData / RESTful web endpoints. It defines uniform field names (e.g. `ListPrice`, `BedroomsTotal`, `StandardStatus`).
3. IDX (Internet Data Exchange) & VOW Feeds
IDX feeds allow participating brokers to display each other's active listings on public agent websites, subject to local MLS compliance rules.
RETS vs RESO Web API vs Managed Web Scraping
| Feature | RETS (Legacy) | RESO Web API | Managed MLS Scraper |
|---|---|---|---|
| Format | XML / COMPACT-DECODED | JSON / OData | JSON / CSV / SQL |
| Licensing Barrier | Requires MLS Brokerage Approval | Requires MLS Brokerage Approval | No Broker License Lock Required |
| Setup Speed | Weeks/Months | Weeks | 24-48 Hours On-Demand |
Need MLS Data Without Complex Licensing?
WebScrapingHub extracts structured MLS property listings and agent contacts directly into custom database feeds.
Explore MLS Data Scraping API