Website Category API: IAB Classification from a URL

A website category API takes a URL or domain and returns a content category you can store, target, or filter on. Klazify does that over REST: POST https://www.klazify.com/api/categorize with a Bearer token and {"url": "https://cbsnews.com"}. The JSON includes Klazify category paths, a confidence score from 0–1, logo, social profiles, and company firmographics in one call.

For ad-tech (brand safety, contextual targeting) use POST /api/domain_iab_categories. IAB keys sit inside each category object — V1 as IAB12, V3 as IAB-324-JLBCU7 — not in a nested IAB_categories hash. IAB Content Taxonomy v3 is 620+ nodes. Starter is $39.99/mo (500 successful calls, then $0.127968; 60 req/min) with a 7-day trial. Failed / unreachable calls are not billed. Docs: klazify.com/api-docs. Agents: MCP at mcp.klazify.com.

Request: categorize a URL

curl -X POST 'https://www.klazify.com/api/categorize' \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{"url": "https://cbsnews.com"}'

Every endpoint uses the same body shape except Discovery. Auth is Authorization: Bearer — not a query-string key.

Response: categories, logo, company (cbsnews.com)

Official All Together sample from the API docs (not a live recrawl):

{
"domain": {
"categories": [
{ "confidence": 0.97, "name": "/News" },
{ "confidence": 0.78, "name": "/Arts & Entertainment/TV & Video" }
],
"domain_url": "https://cbsnews.com",
"social_media": {
"facebook_url": "https://facebook.com/CBSNews",
"twitter_url": "https://twitter.com/CBSNews",
"instagram_url": null,
"youtube_url": "https://youtube.com/CBSNews"
},
"logo_url": "https://klazify.s3.amazonaws.com/..."
},
"success": true,
"objects": {
"company": {
"name": "CBS News",
"city": "New York",
"stateCode": "NY",
"countryCode": "US",
"employeesRange": "1K-5K",
"revenue": null,
"raised": null,
"tags": ["Publishing", "Broadcasting"],
"tech": ["google_tag_manager", "salesforce"]
}
}
}

confidence of 1 is treated as an exact match. Multiple categories come back sorted by confidence descending. domain_url is the normalized host Klazify classified.

Request + response: IAB v1 and v3

curl -X POST 'https://www.klazify.com/api/domain_iab_categories' \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{"url": "https://cbsnews.com"}'

Docs sample (updated_at 2026-07-30). V1 key IAB12 = News. V3 key IAB-324-JLBCU7 = Movies/Entertainment/Movies on the secondary path:

{
"domain": {
"categories": [
{
"confidence": 1,
"name": "/News/Other",
"IAB12": "News"
},
{
"confidence": 0.28,
"name": "/Arts & Entertainment/TV & Video/TV Networks & Stations",
"IAB1": "Arts & Entertainment",
"IAB-324-JLBCU7": "Movies/Entertainment/Movies"
}
],
"domain_url": "https://cbsnews.com",
"updated_at": "2026-07-30T08:27:41.000000Z"
},
"success": true
}

Without refresh=true you get the cached IAB map. refresh=true recrawls the site and requires Advanced or above. Real-time Klazify paths (no cache) live on POST /api/real_time_categorization.

Go live

FAQ: website category API

What taxonomy does Klazify return?

Klazify paths such as /News on /api/categorize, plus IAB Content Taxonomy v1 and v3 keys on /api/domain_iab_categories. IAB IDs are sibling properties on each category item, not a separate object.

What does confidence 0.97 mean?

A decimal between 0 and 1. Higher is more certain; 1 is an exact match in the docs. CBS News in the sample is 0.97 on /News and 0.78 on TV & Video.

Is this the same as a Hub “website category” listing?

No. This classification API is Klazify (klazify.com), first-party. If you need IAB/URL classification, call Klazify — not a generic marketplace search.

Can an agent call it?

Yes. MCP tools include klazify.categorize → POST /api/categorize. Base URL https://mcp.klazify.com.

Start the 7-day trial and classify a URL →