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Real-Time API

Categorize Any URL in Real Time Across Every Major Taxonomy

Send a URL, get back categories in IAB v3, IAB v2, Web Filtering, IPTC, Google Shopping, and Shopify — all in one API call. No batch jobs, no waiting. Instant classification powered by multi-layer NLP and a database of 103 million pre-classified domains.

6Taxonomies Supported
103MDomains Pre-Classified
15+Enrichment Data Fields
RESTSimple JSON API
IAB v3 & v2
Web Filtering
IPTC NewsCodes
Google Shopping
Shopify Taxonomy
Custom Categories
Instant Classification

Every URL Classified in Milliseconds, Not Hours

Real-time URL categorization analyzes and classifies any website the moment you send it to our API. There is no batch queue, no processing delay, and no callback to wait for. You send a URL, and you receive back a structured JSON response containing the full classification across every taxonomy your plan supports.

This is possible because our system combines two approaches: a pre-classified database of 103 million domains that delivers instant lookups for known URLs, and a live analysis pipeline that fetches, renders, and classifies unknown URLs in real time using multi-layer NLP, content extraction, and ensemble machine learning models.

The result is identical whether the URL exists in our database or requires live analysis — a complete set of hierarchical category paths, confidence scores, and optional enrichment data, delivered in one API call.

# Classify a URL in real time curl -X POST \ -H 'Content-Type: application/x-www-form-urlencoded' \ -d 'query=techcrunch.com&api_key=your_api_key&data_type=url' \ 'https://www.websitecategorizationapi.com
/api/iab/iab_web_content_filtering.php'
Under the Hood

How Real-Time Classification Works

Six stages execute in parallel to deliver accurate real-time classification results.

URL Validation & Database Lookup

The URL is validated for structure and immediately checked against our 103-million-domain database. If a fresh classification exists, it is returned instantly without live analysis. Unknown or stale URLs proceed to the live pipeline.

Content Retrieval & Rendering

Our distributed servers fetch the page from multiple geographic locations using headless browser technology. JavaScript is executed, dynamically loaded content is captured, and the full rendered page is extracted — not just static HTML. This ensures we analyze the page as users actually see it.

Multi-Layer NLP Analysis

Natural language processing extracts semantic meaning, key topics, and entity relationships. Structural analysis evaluates page layout and navigation. Metadata extraction processes titles, descriptions, and structured data. All layers run simultaneously.

Ensemble Classification

Proprietary deep learning models process the analyzed features, comparing against training data from over 500 million categorized URLs. The ensemble generates confidence scores for every potential category across all supported taxonomies in one pass.

Confidence Scoring & Ranking

Categories are ranked by confidence level. The system returns the top categories for each taxonomy with scores from 0 to 1, allowing you to set custom thresholds. Primary and secondary categories are both returned so you understand the full content profile.

Response Delivery

The complete classification — categories, confidence scores, and optional enrichment data — is returned in structured JSON. The URL is added to our database for future instant lookups. Cached domains return even faster since they skip the live analysis pipeline.

Multi-Taxonomy

Six Taxonomies Returned in Every Response

No need to maintain multiple categorization services. One API call returns classifications across every major industry standard.

IAB Content Taxonomy v3

The latest IAB Tech Lab standard with 698 categories across a three-tier hierarchy. The default for programmatic advertising, contextual targeting, and content classification. Returned by default on every request. View full taxonomy.

IAB Content Taxonomy v2

The widely adopted predecessor with 400+ categories. Many DSPs and SSPs still operate on v2. We return both v2 and v3 simultaneously so you can support legacy and modern systems without separate API calls. View full taxonomy.

Web Filtering Categories

59 categories built for content filtering, parental controls, and policy enforcement. Covers adult content, violence, gambling, malware, weapons, drugs, and other risk categories that IAB taxonomies deliberately exclude. View all 59 categories.

IPTC NewsCodes

The international standard for news content classification used by news agencies, publishers, and media companies worldwide. Enables granular news topic identification — from politics and economics to science, sports, and entertainment subgenres.

Google Shopping Taxonomy

Google's product categorization with 6,000+ categories used for Shopping ads, Merchant Center feeds, and product data management. Classifies product pages and e-commerce URLs into the exact categories Google uses for advertising.

Shopify Product Taxonomy

Shopify's standardized product classification system. Enables automated categorization of products for e-commerce platforms, feed optimization, and cross-platform product mapping between Shopify, Google, and Amazon category systems.

Infrastructure

Built for Enterprise Scale

Our classification infrastructure handles massive volumes with consistent low-latency performance.

6Taxonomies in one API call
103MDomains pre-classified in database
15+Enrichment data fields available
RESTSimple POST endpoint, JSON response
Ad Tech

Real-Time Categorization for Programmatic Advertising

In programmatic advertising, decisions happen in milliseconds. When a bid request arrives, your system needs to know the content category of the impression URL instantly — there is no time for batch lookups or async callbacks.

Our API fits directly into the bid-request pipeline. DSPs use it to verify that ad placements match brand safety policies before bidding. SSPs use it to classify their inventory in real time for contextual targeting. Ad verification companies use it to audit placements after they serve.

The combination of real-time responses, multi-taxonomy output, and a 103-million-domain pre-classified database means you can make precise, real-time decisions about every impression without compromising on coverage.

  • Pre-bid URL verification for brand safety compliance
  • Contextual targeting based on page-level IAB categories
  • Post-bid placement auditing and quality scoring
  • Inventory classification for SSP sell-side optimization

Bid-Request Flow

1
Bid request arrives
SSP sends impression URL
2
API classifies URL
IAB v3 + Web Filtering in real time
3
Policy engine checks
Brand safety rules evaluated
Bid or no-bid
Decision made in under 100ms total
Applications

Use Cases Beyond Advertising

Real-time categorization serves any system that needs to understand what a URL is about the moment it appears.

Content Filtering

Schools, libraries, ISPs, and parental control software use real-time categorization to allow or block web access based on configured policies. When a user requests a URL, our API classifies it instantly so the filtering system can act before the page loads. Our 59-category Web Filtering taxonomy covers the risk categories that matter for compliance.

Cybersecurity & Threat Detection

Security operations integrate our API into threat detection pipelines. Suspicious URLs found in email attachments, network traffic, or security logs are classified in real time to identify phishing pages, malware distribution sites, and social engineering attacks. The malware detection field provides an additional security layer beyond category classification.

Market Research at Scale

Research teams classify thousands of URLs to map industry verticals, track competitor positioning, and analyze market structure. Real-time processing means you can categorize a fresh list of 100,000 URLs in hours rather than days, using our parallel processing capabilities with up to 500 concurrent threads.

Content Recommendation

Media platforms and content aggregators classify incoming articles and pages in real time to build topic clusters, match content to user interests, and populate category-based feeds. Hierarchical categories enable precision: not just "Technology" but "Technology > Artificial Intelligence > Machine Learning Applications".

COPPA Compliance

Advertisers and publishers use real-time categorization to identify child-directed content before serving ads. Combined with our dedicated COPPA compliance scoring API, you can automate the identification of mixed-audience and child-directed sites that require special advertising treatment under FTC regulations.

AI Agent Guardrails

Autonomous AI agents that browse the web need real-time URL classification to enforce browsing policies. Our API enables agents to check each URL against allowlists and category policies before accessing the page, preventing agents from visiting inappropriate, dangerous, or restricted content.

Integration

Simple REST API, Comprehensive Output

Integration requires a single HTTP GET or POST request with two parameters: the URL to classify and your API key. Optional parameters let you control which taxonomies to return, set confidence thresholds, request enrichment data, and specify timeout behavior.

The API follows REST conventions, returns JSON, and works with any programming language. We provide code examples and guides for Python, JavaScript, PHP, Java, Ruby, and Go. For high-volume use cases, our batch endpoint accepts multiple URLs per request, and our parallel processing guide shows how to classify 150,000+ URLs in under 10 hours.

  • RESTful JSON API — works with any language or framework
  • Batch endpoint for multi-URL requests in one call
  • Parallel processing support for high-volume classification
  • Comprehensive SDK examples and integration guides
  • Transparent rate limiting with clear error responses
# Python — classify a URL import http.client conn = http.client.HTTPSConnection( "www.websitecategorizationapi.com") payload = 'query=bbc.com&api_key=your_api_key&data_type=url' headers = { 'Content-Type': 'application/x-www-form-urlencoded' } conn.request("POST", "/api/iab/iab_web_content_filtering.php", payload, headers) res = conn.getresponse() data = res.read() print(data.decode("utf-8"))
Offline Option

Need Zero-Latency? Download the Full 103M-Domain Database

For applications where zero latency matters — DNS filtering, firewall rules, on-device filtering — we offer the entire classified domain database as an offline download. Over 103 million domains, pre-classified across IAB v3, IAB v2, and Web Filtering taxonomies, delivered as compressed CSV files updated daily.

The offline database gives you the same classification accuracy as our API with true zero latency. Deploy it on-premise, embed it in edge devices, or run it in an air-gapped network. No internet connection needed after the initial download.

Many enterprise clients use a hybrid approach: the offline database for known domains (covering 99.9%+ of internet traffic) and the real-time API as a fallback for newly registered or uncategorized URLs. This delivers the lowest possible latency with complete coverage.

Explore Offline Database

Database Specs

Total domains 103,000,000+
Internet coverage 99.9%+
Update frequency Daily
Taxonomies included IAB v3, v2, WF
Format Compressed CSV
Lookup latency 0ms (local)

Start Categorizing URLs in Real Time

Try the API live with any URL, or view pricing plans to find the right volume for your use case.

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