TechnologyChecker API reference — technology detection REST API

Base URL

All API requests use the following base URL:

https://api.technologychecker.io

Prerequisites

A TechnologyChecker account (sign up free)
Some familiarity with REST APIs and HTTP requests

Quick start

Get your API key

Sign in to app.technologychecker.io and go to Settings > Developers to create an API key. You can hold several keys — one per environment or integration — and manage them all from that same screen. Note that alerts, audiences and lead lists are owned per key, not per account.

Make your first request

Look up any domain’s technology stack:

curl -H "Authorization: Bearer YOUR_API_KEY" \
  https://api.technologychecker.io/v1/domain/shopify.com

import requests

headers = {"Authorization": "Bearer YOUR_API_KEY"}
response = requests.get(
    "https://api.technologychecker.io/v1/domain/shopify.com",
    headers=headers,
)
print(response.json())

const response = await fetch(
  "https://api.technologychecker.io/v1/domain/shopify.com",
  {
    headers: { Authorization: "Bearer YOUR_API_KEY" },
  }
);
const data = await response.json();

Explore the response

{
  "success": true,
  "data": {
    "domain": "shopify.com",
    "active_technologies": [
      {
        "id": 2,
        "name": "Cloudflare",
        "category": "CDN",
        "first_seen": "2020-05-08 00:00:00",
        "last_seen": "2026-01-08 00:00:00",
        "subdomain": "SHOPIFY.COM"
      },
      {
        "id": 4,
        "name": "SSL by Default",
        "category": "SSL/TLS Certificates",
        "first_seen": "2015-09-08 00:00:00",
        "last_seen": "2026-01-08 00:00:00",
        "subdomain": "SHOPIFY.COM"
      }
    ],
    "historical_technologies": [...]
  }
}

Available APIs

Domain technologies

Look up active and historical technologies for any domain. Find websites using a specific technology, track tech stack changes, and build prospecting lists.

Method	Path	Description	Credits
GET	`/v1/domain/{domain}`	Get active and historical technologies for a domain	1
GET	`/v1/domain/{domain}/history`	Get full technology history with active/removed status	1
GET	`/v1/domain/{domain}/changes`	What a domain recently added and dropped, with confidence	1
GET	`/v1/technology/name/{name}/domains`	Find top domains using a specific technology	1

Technology data

Search and look up 40,000+ tracked technologies by name or ID. Get extended metadata and batch-resolve technology names for enrichment pipelines.

Method	Path	Description	Credits
GET	`/v1/technology/{id}/info`	Get extended details (description, website, icon)	1
GET	`/v1/technology/name/{name}`	Quick lookup by exact name (case-insensitive)	1
GET	`/v1/technologies`	Search technologies by name or category	1
POST	`/v1/technologies/lookup`	Batch lookup multiple names in one request	1

Market intelligence

Technology adoption statistics, monthly usage trends spanning 20 years, and category market share. Build competitive analysis reports with data from 50M+ domains.

Method	Path	Description	Credits
GET	`/v1/technology/{id}/stats`	Active and total domain counts	1
GET	`/v1/technology/{id}/history`	Monthly usage trends (up to 20 years)	1
GET	`/v1/category/{id}/market-share`	Market share distribution within a category	1

Company data

Firmographic data from 25.4M LinkedIn company records. Search, filter, and batch-enrich companies by technology, geography, industry, and size.

Method	Path	Description	Credits
GET	`/v1/technology/{id}/companies`	Get companies using a technology (with filters)	1
GET	`/v1/company/{domain}`	Get company data for a specific domain	1
GET	`/v1/companies`	Search and filter companies	1
POST	`/v1/companies/batch`	Batch lookup multiple domains	1 per domain

Live detection

Real-time technology detection with browser rendering (Puppeteer, REST, HTTP modes). Scan any URL not in the pre-crawled database.

Method	Path	Description	Credits
POST	`/v1/technology-lookup-live`	Live technology detection (3 modes: full, light, fetch)	5

Signals

Intent signals derived from technology state transitions: who just adopted, who just dropped, who replaced a competitor, and who has a gap in their stack. All support firmographic filtering, and everything here can be subscribed to as an alert.

Method	Path	Description	Credits
GET	`/v1/signals`	List available signal types and filter vocabulary	0
GET	`/v1/signals/{type}`	Domains that adopted or churned a technology	1
GET	`/v1/signals/switch`	Domains that replaced a competing technology	1
GET	`/v1/signals/whitespace`	Domains with an anchor but a gap in a category	1
GET	`/v1/signals/{type}/export`	CSV export with company and contact columns	1 per row
POST	`/v1/signals/churn/validate`	Live re-detection to confirm a churn	~2–5 per domain

Alerts

Save any signal query with a webhook URL and receive only new matching events, HMAC-signed. Alerts are a plan entitlement — creating, editing and firing them is free.

Method	Path	Description
GET	`/v1/alerts`	List your alerts
POST	`/v1/alerts`	Create an alert (returns the webhook secret)
GET	`/v1/alerts/{id}`	Alert detail including the webhook secret
PATCH	`/v1/alerts/{id}`	Pause, resume or reconfigure
DELETE	`/v1/alerts/{id}`	Delete an alert
POST	`/v1/alerts/{id}/test`	Fire a synthetic payload to test your receiver
GET	`/v1/alerts/{id}/deliveries`	Delivery log for debugging

See alert webhooks for the payload format and signature verification.

Audiences

Saved groups of domains — uploaded lists or computed recipes — that you can profile, slice and keep fresh.

Method	Path	Description	Credits
GET	`/v1/segments`	List your audiences and plan limits	0
POST	`/v1/segments`	Upload a list (free) or compute a recipe	0 or 1
GET	`/v1/segments/{id}`	Audience detail	0
PATCH	`/v1/segments/{id}`	Rename, refresh membership, set crawl cadence	0 or 1
DELETE	`/v1/segments/{id}`	Delete an audience	0
GET	`/v1/segments/{id}/domains`	Page through member domains	0
GET	`/v1/segments/{id}/technologies`	What this group runs, with data freshness	1
GET	`/v1/segments/{id}/breakdown`	Composition by country, industry, size, category	1
GET	`/v1/segments/stats`	One technology’s footprint inside a slice	1
POST	`/v1/segments/{id}/crawl`	Re-scan members on demand	1 per domain
GET	`/v1/segments/{id}/crawls`	Crawl dispatch history and spend	0

Lead lists

Build and export targeted domain lists combining technology detection with company and contact data. Creation runs as a background job billed on actual rows delivered.

Method	Path	Description	Credits
GET	`/v1/leads/technologies/search`	Search technologies with domain counts	0
GET	`/v1/leads/tech-map`	Technology id to name mapping	0
POST	`/v1/leads/preview-count`	Estimate matches and cost before building	0
POST	`/v1/leads/create`	Build a list (async)	1 per row
GET	`/v1/leads/lists`	List your lead lists	0
GET	`/v1/leads/lists/{id}`	List detail and build status	0
GET	`/v1/leads/lists/{id}/preview`	Page through rows with search and sorting	0
GET	`/v1/leads/lists/{id}/export`	Download as CSV or JSON	0
DELETE	`/v1/leads/lists/{id}`	Delete a list	0

Account

Monitor API usage and credit consumption, and manage your API keys. These endpoints are free and don’t consume credits.

Method	Path	Description
GET	`/v1/usage`	Aggregated usage statistics
GET	`/v1/credits`	Credit balance and reset date
GET	`/v1/keys`	List your API keys
POST	`/v1/keys`	Create a key (secret shown once)
GET	`/v1/keys/{key_id}`	Key detail
PATCH	`/v1/keys/{key_id}`	Rename a key
DELETE	`/v1/keys/{key_id}`	Revoke a key
GET	`/v1/keys/{key_id}/usage`	Per-key timeline and endpoint breakdown

Essentials

Authentication

Bearer token setup and key management.

Rate limits

Request limits by plan and retry handling.

Credits

Credit costs per endpoint and plan details.

Interactive testing

You can test all endpoints directly from the API playground in your dashboard. Your API key is pre-filled automatically.

API Playground showing Technology APIs and Company Data APIs with interactive Try in API Console buttons for each endpoint

Frequently asked questions

Which endpoint should I use to look up a website's technologies?

Use GET /v1/domain/{domain} for an instant lookup from the pre-crawled database of 50M+ domains (1 credit). If the domain isn’t found, use POST /v1/technology-lookup-live for real-time detection (5 credits).

How do I find companies using a specific technology?

First, look up the technology name with GET /v1/technology/name/{name} to get its ID. Then call GET /v1/technology/{id}/companies with optional filters for country, industry, and employee count.

Can I look up multiple domains or technologies in one request?

Yes. Use POST /v1/companies/batch to enrich multiple domains with company data in a single call (1 credit per domain). Use POST /v1/technologies/lookup to resolve multiple technology names to IDs in one request (1 credit).

How do I find out who just started or stopped using a technology?

Use the signals endpoints. GET /v1/signals/adoption returns domains that newly started using a technology in a window, and GET /v1/signals/churn returns those that dropped it. Add firmographic filters like country and employees to narrow to your ICP. To be notified rather than polling, save the same query as an alert.

What is the difference between signals, audiences and lead lists?

They answer three different questions. Signals ask “what just changed?” and return events, scoped by technology or category. Audiences ask “what is true of this group?” — you save a set of domains and profile its stack and composition. Lead lists ask “give me the rows” and produce a downloadable file with company and contact data, billed per row. A common flow runs through all three: find a signal, save the matches as an audience, export it as a lead list.

Is the TechnologyChecker API free to use?

Yes. The Free plan gives you 100 credits per month with full API access — no credit card required. Most endpoints cost 1 credit per request. If you need more volume, the Pro plan (

89/month) includes 10,000 credits and the Scale plan (

249/month) includes 50,000. See credits and pricing for the full breakdown.

What programming languages work with the TechnologyChecker API?

Any language that can make HTTP requests works with the API. It’s a standard REST API that returns JSON responses. The docs include code examples in cURL, Python, and JavaScript, but you can use Ruby, Go, Java, PHP, C#, or any other language with an HTTP client. No SDK installation is required.

How many technologies does TechnologyChecker track?

TechnologyChecker tracks over 40,000 technologies across categories like CDNs, analytics, CMS platforms, e-commerce frameworks, payment processors, and more. The database covers 50M+ actively monitored domains with historical data going back up to 20 years. Use GET /v1/technologies to search the full catalog.

​Base URL

​Prerequisites

​Quick start

​Available APIs

​Domain technologies

​Technology data

​Market intelligence

​Company data

​Live detection

​Signals

​Alerts

​Audiences

​Lead lists

​Account

​Essentials