Reference Guide

US MLS Directory

Complete reference guide to MLS systems, RESO standards, and IDX data access across the United States. Find your local MLS and understand your data feed options.

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National Organizations

Aggregation Platforms

100+

Regional MLSs

1M+

Total Subscribers

National Organizations & Standards Bodies

National Association of REALTORS (NAR)

IDX Policy Statement 7.58 governing all MLS IDX rules

RESO (Real Estate Standards Organization)

Web API and Data Dictionary standards

RESO Certification Portal

Verify MLS RESO certification status

Council of MLS (CMLS)

MLS industry trade organization

Data Aggregation Platforms

Unified API access to multiple MLSs through a single integration

MLS Grid

Recommended

30+ MLSs, single RESO-compliant license

Trestle (CoreLogic/Cotality)

90+ MLSs, RESO Platinum certified

Bridge Interactive (Zillow)

RESO Data Dictionary compliant

ListHub (realtor.com)

Listing syndication aggregator

Key IDX Resources

NAR IDX Policy

Policy Statement 7.58

RESO Web API Docs

Technical API specifications

RESO Data Dictionary

Standardized field definitions

RESO UOI Database

Unique Organization Identifiers

Top 10 Largest MLS Systems

By subscriber count (REALTOR members with MLS access)

Rank	MLS	Coverage	Subscribers
1	California Regional MLS (CRMLS)	Southern California	110,000+
2	Bright MLS	Mid-Atlantic (6 states + DC)	100,000+
3	Stellar MLS	Florida	70,000+
4	Houston Association of REALTORS (HAR)	Greater Houston	50,000+
5	Arizona Regional MLS (ARMLS)	Phoenix Metro	45,000+
6	REcolorado	Denver Metro	30,000+
7	Northwest MLS (NWMLS)	Washington State	30,000+
8	Georgia MLS	Georgia Statewide	28,000+
9	Midwest Real Estate Data (MRED)	Chicago Metro	25,000+
10	Las Vegas REALTORS MLS	Southern Nevada	17,000+

Regional MLS Directory

Massachusetts

MLS	Coverage	Subscribers	Link
MLS PIN	New England (MA primary)	35,000+

New York

MLS	Coverage	Subscribers	Link
OneKey MLS	Long Island + NYC	40,000+
NY State MLS	Upstate New York	Regional

Connecticut

MLS	Coverage	Subscribers	Link
SmartMLS	Connecticut statewide	18,000+

New Jersey

MLS	Coverage	Subscribers
NJMLS	Northern NJ	11,000+
Bright MLS (NJ)	Central/South NJ	Part of 100k+
Garden State MLS	Regional NJ	Regional
Monmouth Ocean MLS	Shore region	Regional

Pennsylvania

MLS	Coverage	Subscribers	Link
Bright MLS (PA)	Eastern PA + Philly	Part of 100k+
West Penn MLS	Pittsburgh/Western PA	Regional

DC / Maryland / Virginia

MLS	Coverage	Subscribers	Link
Bright MLS	DC + MD + VA + 4 more states	100,000+

Florida

MLS	Coverage	Subscribers
Stellar MLS	Central FL, Tampa, Orlando	70,000+
Miami Association (MLS)	Miami-Dade	50,000+
BeachesMLS	Palm Beaches	15,000+
Broward-Palm Beach MLS	South FL	Regional
SWFL MLS	Naples/Ft Myers	Regional
Northeast Florida MLS	Jacksonville	Regional

Georgia

MLS	Coverage	Subscribers	Link
Georgia MLS	Statewide	28,000+
FMLS	Atlanta Metro	15,000+

North Carolina

MLS	Coverage	Subscribers
Canopy MLS	Charlotte region	19,000+
Triangle MLS	Raleigh-Durham	12,000+
Triad MLS	Greensboro/Winston-Salem	Regional

South Carolina

MLS	Coverage	Subscribers	Link
SC REALTORS MLS	Statewide	Regional
Charleston Trident MLS	Charleston area	Regional

Tennessee

MLS	Coverage	Subscribers	Link
Realtracs	Nashville/Middle TN	15,000+
Memphis Area MLS	Memphis metro	Regional

Illinois

MLS	Coverage	Subscribers	Link
MRED	Chicago + suburbs	25,000+

Ohio

MLS	Coverage	Subscribers
MLS Now	Cleveland + NE Ohio	10,000+
Columbus REALTORS MLS	Central Ohio	9,000+
Cincinnati MLS	Cincinnati/SW Ohio	Regional

Michigan

MLS	Coverage	Subscribers	Link
Realcomp	SE Michigan / Detroit	15,000+
MiRealSource	Statewide	Regional

Indiana

MLS	Coverage	Subscribers	Link
MIBOR (BLC)	Indianapolis	12,000+

Minnesota

MLS	Coverage	Subscribers	Link
NorthstarMLS	Minneapolis-St. Paul	20,000+

Wisconsin

MLS	Coverage	Subscribers	Link
Metro MLS	Milwaukee + SE Wisconsin	8,000+

Missouri

MLS	Coverage	Subscribers	Link
MARIS	St. Louis metro	10,000+
Heartland MLS	Kansas City	12,000+

Kansas

MLS	Coverage	Subscribers	Link
Heartland MLS (KS)	KC metro Kansas side	Part of 12k+

Texas

MLS	Coverage	Subscribers
HAR (Houston)	Greater Houston	50,000+
NTREIS (Dallas)	Dallas-Fort Worth	40,000+
ABOR (Austin)	Austin metro	16,000+
SABOR (San Antonio)	San Antonio	13,000+
El Paso Association MLS	El Paso	Regional

Oklahoma

MLS	Coverage	Subscribers	Link
MLSOK	Oklahoma City + Tulsa	8,000+

Louisiana

MLS	Coverage	Subscribers	Link
GSREIN	New Orleans + Gulf South	Regional

Arkansas

MLS	Coverage	Subscribers	Link
Cooperative Arkansas REALTORS MLS	Statewide	Regional

Colorado

MLS	Coverage	Subscribers
REcolorado	Denver metro	26,000+
IRES	Northern CO Front Range	7,000+
PPMLS	Colorado Springs	6,000+
CREN	Mountain resorts	Regional

Arizona

MLS	Coverage	Subscribers
ARMLS	Phoenix metro	40,000+
MLSSAZ	Tucson, Southern AZ	Regional
WARDEX	Western AZ	1,100+

Nevada

MLS	Coverage	Subscribers	Link
Las Vegas REALTORS MLS	Southern Nevada	17,000+
NNRMLS	Reno / Northern NV	4,000+

Utah

MLS	Coverage	Subscribers	Link
UtahRealEstate.com (WFRMLS)	Utah statewide (97%+ coverage)	—

New Mexico

MLS	Coverage	Subscribers	Link
SWMLS / GAAR	Albuquerque	—
SFAR	Santa Fe	—

Idaho

MLS	Coverage	Subscribers	Link
Intermountain MLS	Boise area	—
Snake River MLS	Eastern Idaho	—

Montana / Wyoming

MLS	Coverage	Subscribers	Link
Montana Regional MLS	Montana	—
Wyoming MLS	Wyoming statewide	—

California

MLS	Coverage	Subscribers
CRMLS	SoCal + Central CA	110,000+
MLSListings	SF Bay Area + Central Coast	18,000+
Bay East AOR MLS	East Bay	Regional
BAREIS MLS	North Bay	12,000+
MetroList	Sacramento	20,000+
San Diego MLS	San Diego County	19,000+

Washington

MLS	Coverage	Subscribers	Link
NWMLS	Seattle + most of WA	30,000+
Spokane MLS	Eastern WA	Regional

Oregon

MLS	Coverage	Subscribers	Link
RMLS	Portland metro	12,000+
Willamette Valley MLS	Central Oregon	Regional

Hawaii

MLS	Coverage	Subscribers	Link
HiCentral MLS	All islands	10,000+

Alaska

MLS	Coverage	Subscribers	Link
Alaska MLS	Statewide	3,000+

Data Feed Platforms Comparison

Choose the right platform based on your coverage needs and technical requirements

MLS Grid

Recommended

30+ MLS systems
Single RESO-compliant license
Unified API across all MLSs
Real-time data updates

Learn more

Trestle (CoreLogic)

90+ MLS systems
RESO Platinum certified
Enterprise-grade SLA
Historical data access

Learn more

Bridge Interactive (Zillow)

RESO Data Dictionary compliant
Zillow ecosystem integration
RESTful API design

Learn more

ListHub (realtor.com)

Listing syndication focus
Wide portal distribution
Performance analytics

Learn more

Integration Guide

RESO Web API

The modern standard for MLS data access. RESTful endpoints with OAuth 2.0 authentication.

OData query syntax for filtering
JSON response format
Standardized field names (Data Dictionary)
Real-time or near-real-time updates

Legacy RETS

Older standard still used by some MLSs. Being phased out in favor of RESO Web API.

XML-based responses
DMQL query language
Non-standardized field names per MLS
Being deprecated by most MLSs

HomeStar Integration

HomeStar handles all MLS integration complexity for you. We support:

MLSGrid

Recommended. Single license covers 30+ MLSs.

RESO Web API

Direct connections to any certified MLS.

Legacy RETS

Support for older MLS systems.

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Related Data Partners

RentCast Property Data

Home valuations, market analytics, and property data enrichment. Powers our instant valuation and market report features.

Learn more

More Integrations Coming

We're always adding new data partners to enrich your listings and provide more insights.

Ready to Connect Your MLS?

HomeStar handles all the complexity of MLS integration. Tell us which MLS you use, and we'll take care of the rest.

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