API Documentation • NAICS Lookup API

NAICS Lookup API

Comprehensive NAICS (North American Industry Classification System) code lookup API with hierarchy navigation, year-to-year crosswalks, SIC mapping, and full-text search. All data sourced from the U.S. Census Bureau, hosted locally for sub-20ms response times.

https://naics.datasourceapi.com/api/v1

OpenAPI Spec

Response Format

All endpoints return JSON with this envelope structure:

{
  "request_status": "success",
  "message": "Found NAICS code 511210 (2022)",
  "data": { ... },
  "data_sources": [{
    "source": "census_naics",
    "dataset": "NAICS 2022",
    "cache": "hit"
  }]
}

Valid years: 2022 (default), 2017, 2012, 2007

Endpoints

GET /code/{code} Look up a NAICS code

Returns the full profile for a NAICS code including title, hierarchy, children, description, examples, and crosswalks.

Parameter	Location	Description
code required	path	NAICS code (2-6 digits, e.g. `511210`)
year optional	query	NAICS revision year (default: 2022)

Try it: 511210

{
  "code": "511210",
  "year": 2022,
  "title": "Software Publishers",
  "level": 6,
  "level_name": "National Industry",
  "sector_code": "51",
  "ancestors": [...],
  "children": [],
  "crosswalks": [...]
}

GET /search Search NAICS codes by keyword or code prefix

Autocomplete-ready search. Matches code prefixes (numeric query) or title keywords (text query).

Parameter	Location	Description
q required	query	Search query (min 2 chars). E.g. `software` or `5112`
year optional	query	NAICS revision year (default: 2022)
level optional	query	Filter by hierarchy level (2-6)
limit optional	query	Max results (default: 20, max: 50)

Try it: software

GET /code/{code}/children Get direct children in hierarchy

Returns all direct sub-categories of a NAICS code. E.g. for sector 51, returns subsectors like 511, 512, etc.

Parameter	Location	Description
code required	path	NAICS code
year optional	query	NAICS year (default: 2022)

Try it: 51/children

GET /code/{code}/ancestors Get path from sector to this code

Returns the full hierarchy path from the root sector down to this code.

Parameter	Location	Description
code required	path	NAICS code
year optional	query	NAICS year (default: 2022)

Try it: 511210/ancestors

GET /code/{code}/history Code across all NAICS revisions

Shows how a code has existed across NAICS revision years, including title changes.

Try it: 511210/history

GET /sectors List all 20 economic sectors

Returns all 20 NAICS economic sectors for the specified year.

Parameter	Location	Description
year optional	query	NAICS year (default: 2022)

Try it

GET /sector/{code} Sector details with subsectors

Returns a sector profile with its subsector tree.

Try it: sector 51

GET /year/{year} Year summary with code counts

Summary of a NAICS revision year: total codes, breakdown by level, and sector list.

Try it: 2022

GET /crosswalk Map a code between NAICS years

Returns the concordance mapping for a code from one NAICS revision to another. Shows splits, merges, and 1:1 mappings.

Parameter	Location	Description
code required	query	NAICS code to map
from required	query	Source year
to required	query	Target year

Try it: 511210 (2022 to 2017)

GET /changes Changes between NAICS revisions

Lists all codes that changed between two NAICS revision years (new, split, merged, title changes).

Parameter	Location	Description
from optional	query	From year (default: 2017)
to optional	query	To year (default: 2022)

Try it: 2017 to 2022

GET /sic/{code} SIC to NAICS mapping

Maps a 4-digit Standard Industrial Classification (SIC) code to its NAICS equivalents.

Try it: SIC 7372

GET /compare Compare multiple NAICS codes

Returns profiles for multiple codes side-by-side. Useful for comparing related industries.

Parameter	Location	Description
codes required	query	Comma-separated codes (2-10)
year optional	query	NAICS year (default: 2022)

Try it

POST /bulk/lookup Bulk code lookup (up to 500)

Look up multiple NAICS codes in a single request. Send a JSON body with an array of codes.

POST /api/v1/bulk/lookup
Content-Type: application/json

{
  "codes": ["511210", "722511", "541511"],
  "year": 2022
}

GET /stats Dataset metadata and statistics

Returns global dataset statistics: total codes, available years, sector count, and data source info.

Try it

Rate Limits & Usage

No API key required — all endpoints are publicly accessible
CORS enabled — call from any origin
Rate limit: 1,000 requests per minute per IP (generous for most use cases)
Response format: JSON only
Caching: KV-backed responses typically resolve in <20ms
Data freshness: Updated when new NAICS revisions are published (approximately every 5 years)

NAICS Hierarchy Levels

Level	Name	Digits	Example
2	Sector	2-digit	51 Information
3	Subsector	3-digit	511 Publishing Industries
4	Industry Group	4-digit	5112 Software Publishers
5	NAICS Industry	5-digit	51121 Software Publishers
6	National Industry	6-digit	511210 Software Publishers

Data Source: U.S. Census Bureau — www.census.gov/naics/ • All data hosted locally for maximum performance