The 12 Best Free Sources for US Parcel Data (and When to Pay)

68% of US counties publish parcel data for free. Yet most GIS analysts spend weeks chasing it down, downloading corrupted shapefiles, and stitching together formats that refuse to play nice. The problem is not availability—it is knowing where to look and recognizing when the free route costs more than paying.

This guide breaks down the 12 best free sources for US parcel data, what you can realistically expect from them, and the hidden costs that trip up experienced teams.

What Free Parcel Data Actually Gets You

Free parcel data comes with trade-offs. Understanding them upfront saves hours of frustration.

Most free data works fine for one-off research or small zones. For production systems or multi-county analysis, the hidden costs—time, cleaning, integration work—often exceed a commercial license.

How to Evaluate Any Parcel Data Source

Before downloading anything, run through this decision framework:

This loop is where the hidden costs accumulate. Every new county means a new format, new field names, and new quality issues.

Tier 1: National Aggregators

These are your starting points. They cover wide areas but vary in depth.

1. USGS National Map Parcel Viewer

The USGS maintains a parcel viewer that aggregates data from thousands of local sources. It is a secondary source—data flows from counties to USGS—so use it to identify which counties have authoritative data, then go direct.

Best for: Identifying which counties have parcel data and finding direct links to county assessor portals.

2. Regrid Free Parcel Layer

Regrid offers a free parcel boundary tile layer. You get visual boundaries without the attribute depth. Their Data Store sells individual counties for one-off downloads.

Best for: Quick visualizations and identifying parcel footprints before committing to data purchase.

3. ESRI Living Atlas Parcel Layers

Esri includes parcel boundary layers in their Living Atlas, accessible to ArcGIS Online users. Coverage varies by region.

Best for: ArcGIS users who need quick parcel context without leaving their stack.

Tier 2: Statewide Clearinghouses

Some states centralize parcel data through state GIS programs. These beat scattered county sites.

4. Alaska Open Data Geoportal

Alaska's statewide parcel data lives in the Alaska Open Data Geoportal, coordinated by the Alaska Geospatial Office.

Best for: Alaska projects—one of the few states with truly centralized parcel distribution.

5. AZGEO Clearinghouse (Arizona)

The Arizona Geographic Information Council runs AZGEO. Registration is free. Once in, you get access to parcel and cadastral data from counties across the state.

Best for: Arizona-wide projects where county-by-county hunting is inefficient.

6. Cal-Atlas (California)

California pulls together spatial data through Cal-Atlas. Individual county assessor portals remain the authoritative source, but Cal-Atlas indexes them.

Best for: California projects where you need to identify which counties have open parcel data.

7. Data.gov

Data.gov hosts thousands of federal, state, and local datasets. Filter by "parcel" or "cadastral" plus your state or county. Quality varies—some datasets are current, others are years stale.

Best for: Discovering obscure local datasets that do not surface on search engines.

Tier 3: Direct County Sources

For the strongest quality and latest updates, go straight to the source.

8. County Assessor GIS Portals

Most counties with parcel data publish it through an assessor's office or GIS department. Search patterns that work:

• "[County name] assessor parcel map"
• "[County name] GIS data download"
• "[County name] open data portal"

Best for: Maximum freshness and complete attribute tables directly from the authority.

9. Open Data Network (Socrata-Powered Portals)

Many counties use Socrata-powered open data portals. Search Open Data Network for your target area. Cities like Temecula, CA publish parcel data directly through these interfaces.

Best for: Counties with modern open data programs—often faster than navigating legacy assessor sites.

10. University GIS Guides

Universities maintain quality GIS resource lists. The Washington University GIS Data Guide and Purdue GIS Data Guide link directly to statewide and county-level parcel sources organized by location.

Best for: Research projects and discovering sources outside your immediate target area.

Tier 4: Specialized Sources

11. Bureau of Land Management (BLM) GIS Data

For western states, the BLM GIS data portal provides cadastral data including township, range, section grids, and federal land boundaries.

Best for: Projects involving federal lands, grazing permits, or mineral rights.

12. Zillow Research Data

Zillow publishes aggregated real estate datasets for research. While not traditional parcel data, their datasets include geographic identifiers and property characteristics.

Best for: Research where property characteristics matter more than legal parcel boundaries.

The Real Cost of Free Data

Free parcel data is not free. Here is where the costs hide:

Integration time. Every county uses different field names. PARCELNBR in one county is PIN in another. Expect 4-8 hours per county just normalizing schemas.

Update tracking. Free sources do not notify you when data updates. You need workflows to check for updates—monthly for some counties, annually for others.

Coverage gaps. Approximately one-third of US counties have limited or no freely accessible parcel data. Those gaps usually hit rural areas where you need coverage for infrastructure projects.

Quality issues. Free data contains errors. Typos in addresses. Misaligned geometries. Missing attributes. Commercial providers invest in QA—free sources do not.

Format conversion. Counties publish in whatever format their GIS vendor supports. Converting from proprietary GDB files or CAD formats adds friction.

When to Pay for Parcel Data

Free data works for:

• One-off research on a single county
• Visual reference without deep attribute needs
• Academic projects with time budgets for cleaning
• Prototyping before committing to a data budget

Pay for commercial data when:

• You need nationwide or multi-state coverage
• Your system depends on consistent schemas
• You are building a production application
• Timeliness matters (monthly updates)
• You need historical snapshots for trend analysis
• Your team lacks bandwidth for data cleaning

Evaluating Commercial Providers

If you decide to pay, check these dimensions:

Coverage completeness. Do they have every county you need? Many providers claim "nationwide" but have gaps in rural areas.

Update frequency. Monthly is standard for quality providers. Anything less and your data drifts.

Schema consistency. Will the same field name mean the same thing across all counties? Inconsistent schemas break automated pipelines.

Delivery format. API access beats bulk downloads for most applications. GeoJSON, Parquet, and vector tiles indicate modern infrastructure.

Pricing transparency. Some providers hide pricing behind sales calls. Others publish clear per-county rates. ATTOM removed their pricing page in early 2026—most buyers find this frustrating.

Provenance documentation. Can the provider tell you the source of every record and when it was last refreshed? Source transparency matters for compliance and accuracy.

Quick Evaluation Checklist

Before committing to a free or paid source, verify:

• Does the coverage match your project area exactly?
• Are update dates published for your counties of interest?
• Can you preview attributes before downloading?
• Is the format usable in your stack (no proprietary conversions)?
• Does the schema match your existing data?
• Are there usage restrictions (academic-only, no commercial use)?

Start Small

Do not build systems around data you have not tested. Download a single county. Load it into your stack. Verify the geometry aligns with your basemap. Check the attributes contain the fields you need. Confirm the update schedule matches your requirements.

Parcel data is foundational. Bad foundations collapse under production load. Test before you scale.

Need parcel data without the hunt? GetParcelData maintains 150M+ parcels nationwide with monthly updates, consistent schemas, and transparent per-county pricing. Get a free sample for any US county.

See coverage and request a sample →