API review

BuiltWith API review

Website technology-detection database and API: what a domain runs (127,960 tracked technologies) with history and spend estimates, plus lists of every site using a technology. Best for front-end / web technographics per domain with first/last detected dates.

Verified 25 Oct 2026 · 45 endpoints listed · Official MCP server
See pricing
BuiltWith API docs

What a call costs

The actions you pay for, as BuiltWith prices them.

ActionCostPer
Domain/Bulk/Relationships/Company-to-URL/Tags/Recommendations/Redirects/Keywords/Product/Trust/Vector/Ask lookup1credit
VAT lookup that returns data1credit (0 if no data)
Free, Trends, WhoAmI, Usage, MCP registry0credit
X402 pay-per-call /agent/*0.0495USD (USDC) per call

Pricing, plan by plan

US dollars, as BuiltWith's pricing page shows them on 25 Oct 2026. Monthly and annual billing are shown apart.

Free tier Free individual site lookups on the website forever; API free endpoints: WhoAmI, Usage, Free API, Trends, MCP registry

Basic

$295/mo

billed monthly

$245.83/mo

billed annually ($2,950 a year)

2 technologies, 2 keywords, 2 retail reports, 1 login, CRM integration

Pro

$495/mo

billed monthly

$412.50/mo

billed annually ($4,950 a year)

unlimited technologies, keywords, retail reports; 1 login

Team

$995/mo

billed monthly

$829.17/mo

billed annually ($9,950 a year)

unlimited; unlimited Pro logins (Team Ultra also available)

API credits (account)

minimum 2,000 credits, bought in 2,000 increments; exact tier price returned at checkout

API included

API credits (guest via Stripe MPP)

10+ credits at $0.0495 each up to 1,999 ($0.50 minimum); token valid 1-720 h

API included

x402 prepaid lookup units (Base USDC)

One-off pack

min 2,000 units; 2,000 = $99, 10,000 = $259; units never expire; tiers: 1-2000: $0.0495; 2001-10000: $0.0200; 10001-50000: $0.0100; 50001-150000: $0.0065; 150001-500000: $0.0045; 500001-1000000: $0.00710; 1000001-2000000: $0.00195; 2000001-5000000: $0.00190; 5000001-10000000: $0.00150; 10000001-+: $0.00100

API included

Plans are monthly (min term 1 month) or yearly (min 1 year). Yearly USD prices (plans page price-toggle script): Basic $2,950/yr, Pro $4,950/yr, Team $9,950/yr, i.e. 10x the monthly price. The page also shows an INR approximation (₹28,009/mo Basic) because of our Indian IP; ignore it. Plans bought via MPP are non-recurring and last one calendar month.

Rate limits

Maximum 8 concurrent requests and 10 requests per second per key; HTTP 429 beyond.

More on limitsLess

The free 0-credit endpoints (Free API, Trends, WhoAmI, Usage, MCP registry) are rate limited to 1 request/sec per key instead. Dedicated endpoints by arrangement.

How to get an API key

BuiltWith uses API key. The steps below follow BuiltWith's own docs.

  1. Create a BuiltWith account. API access starts on the API credits (account) plan.
  2. BuiltWith account; or agent device-code flow (POST /agent-auth/start, user approves in browser)
  3. Make a first call: Account limits, per-endpoint credit costs, batch sizes, privacy flags. Keep the key in an environment variable, never in the command.
    curl -X GET "https://api.builtwith.com/whoamiv1/api.json" \
  -H "Authorization: API $BUILTWITH_API_KEY"

Where the docs live

WhatWhere
Documentationapi.builtwith.com
API referenceapi.builtwith.com/llms-full.txt
OpenAPI specapi.builtwith.com/openapi.json
llms.txtapi.builtwith.com/llms.txt
Base URLhttps://api.builtwith.com
MCP serverhttps://api.builtwith.com/mcp
SDKsbuiltwith-official-cli (npm, includes MCP stdio server)

Strengths and limits

Where it fits

  • Front-end / web technographics per domain with first/last detected dates
  • Prospect lists of sites using technology X with spend, revenue and employee filters
  • Ecommerce research (product, SKU, sales revenue)
  • Tech adds/removals (Change API) and a WebSocket live feed of new detections

Where it falls short

  • Back-end or internal tools that leave no web footprint (use job-post technographics: TheirStack, PredictLeads)
  • Contact data
  • Cheap self-serve list pulls: Lists and Keyword Search need a $295+/month plan

Worth knowing

  • Lists API and Keyword Search API require a subscription; buying lookup credits does not unlock Lists.
  • Bulk job results are deleted after the first successful read: store them immediately.
  • Relationships API charges again if the 10-minute cache expires or the request hits another server.
  • Only 10 req/s and 8 concurrent per key.
  • Validate TECH names for free with the Trends API before paying for Lists calls.
5 moreShow fewer
  • Account credit purchases have a 2,000-credit minimum; tier prices for accounts are not published, only returned at checkout.
  • x402 descriptor lists the 500,001-1,000,000 tier at $0.00710/unit, higher than the 150,001-500,000 tier ($0.0045): looks like a vendor typo, confirm via x402-pricing before buying.
  • No sandbox: testing hits production with a real key.
  • Terms: API access restricted to licensed Customers; internal business use only; no resale, no providing BuiltWith data to third-party data providers or analytics platforms, no bulk extraction beyond licensed datasets, no training competing AI.
  • Minimum term 1 month (monthly) or 1 year (yearly); cancellation keeps the plan active to the end of the term.

Who should use it

Use BuiltWith for
Front-end / web technographics per domain with first/last detected dates
Look elsewhere for
Back-end or internal tools that leave no web footprint (use job-post technographics: TheirStack, PredictLeads)

If BuiltWith is not the answer

Other Enrichment tools in this directory, each with its own review.

BetterContact
Enrichment
From $15/mo

Best for one-bill access to 20+ email/phone providers without holding their keys.

BetterContact API review
Clearbit
Enrichment

Best for existing Clearbit API customers maintaining legacy integrations.

Clearbit API review
Findymail
Enrichment
From $41/moOfficial MCP

Best for high-value contacts where a contractual <5% bounce guarantee matters.

Findymail API review

Before you build

Four things to settle first, each read off BuiltWith's own pages.

  • Confirm the API is on your planAPI access starts on the API credits (account) plan. Free tier: Free individual site lookups on the website forever.
  • Keep the key out of your codeAPI key.
  • Design around the rate limitMaximum 8 concurrent requests and 10 requests per second per key; HTTP 429 beyond.
  • Know the catch before you scaleLists API and Keyword Search API require a subscription; buying lookup credits does not unlock Lists.

Want us to build it for you?

Tell us what you want BuiltWith to do in your stack. We will show you how we would wire it into your data, outbound or CRM, and what we would check first.

Book a call
See case studies

Read from builtwith.com/plans and api.builtwith.com/llms-full.txt. Verified 25 Oct 2026.

All 45 endpointsFor developers: method, path, what it does and what it costs.

Base URL: api.builtwith.com

Bulk and async: Bulk Domain API up to 5,000 domains per job (async 202 + polling); results deleted after first read. Datasets sold separately.

Webhooks: No webhooks documented; Live Feed is a WebSocket (wss://sync.builtwith.com) requiring an active plan

45 endpoints
MethodPathWhat it doesCost
GET/whoamiv1/api.jsonAccount limits, per-endpoint credit costs, batch sizes, privacy flags0
GET/usagev2/api.{json|xml}Credit balance0
GET/v26/api.{json|xml|csv|xlsx}Domain API: technologies (with confidence 0-1), first/last detected, spend history, company meta1 credit per domain; TRUST=yes adds 1
POSTasync/v23/domain/bulkBulk Domain submit1 credit per domain
GETasync/v23/domain/bulk/{job_id}Bulk job status0
GETasync/v23/domain/bulk/{job_id}/resultBulk job result (deleted after first successful read)Not stated
GET/change1/api.jsonTechnology additions/removalsNot stated
GET/lists13/api.{json|xml|txt|csv|tsv}Sites using a technology (prospect lists)requires a subscription (see WhoAmI credits.costs.lists_api)
GET/ask1/api.{json|xml|txt|csv|tsv}Natural-language website list lookups1 credit per query
GET/rv5/api.{json|xml|csv|tsv}Relationships between sites (shared analytics IDs, hosting, ownership)1 credit per key/domain across pages while 10-minute cache is active
GET/free1/api.{json|xml}Summary counts and update ranges by technology group0
GET/ctu3/api.{json|xml}Company name to domains1 per lookup
GET/tag1/api.{json|xml}Domains related to IPs and attributes1 per lookup
GET/rec1/api.{json|xml}Technology recommendations for a domain1 per lookup
GET/redirect1/api.{json|xml}Live and historical redirects1 per lookup
GET/kw2/api.{json|xml}Keywords for a domain1 per lookup
GET/kws1/api.{json|csv}Websites containing a keywordrequires a subscription (see WhoAmI credits.costs.keyword_search_api)
GET/trends/v6/api.{json|xml}Technology trend metadata; validates TECH names0
GET/productv1/api.jsonWebsites selling a product1 per lookup
GET/trustv2/api.{json|xml}Trust/fraud signals and content-safety flags1 per lookup (+1 for LIVE)
GET/vector/v1/api.{json|xml|csv}Semantic search over technologies/categories1 per search
GET/vat1/api.{json|xml|csv}VAT/GSTIN/CNPJ and other registration numbers1 per domain that returns data; 0 otherwise
GET/mcp2/api.{json|xml|csv|txt}Search BuiltWith's registry of remote MCP servers0
WSSwss: //sync.builtwith.com/wss/newLive Feed of new detections (or /wss/channel/<Tech>)requires active plan; trial users get redacted domains
POSThttps://api.builtwith.com/agent-auth/startAgent device-code auth start0
POSThttps://api.builtwith.com/agent-auth/tokenPoll for temporary bw- token (24h)0
GEThttps://payments.builtwith.com/v1/billing/api-discoveryCredit totals (Agent Billing Key)0
GEThttps://payments.builtwith.com/v1/billing/api-configurationSpending limits0
POSThttps://payments.builtwith.com/v1/billing/api-purchaseBuy account credits on saved Stripe cardcharges card
GEThttps://payments.builtwith.com/v1/mpp/catalogStripe MPP catalog (guest purchase)0
POSThttps://payments.builtwith.com/v1/mpp/purchaseStripe MPP purchaseguest: $0.0495 per credit, $0.50 minimum
GET/agent/domainx402 pay-per-call: Look up a domain's technologies and metadata$0.0495 USDC per call (x402, no account)
POST/agent/relationshipsx402 pay-per-call: Find websites related to a domain$0.0495 USDC per call (x402, no account)
POST/agent/changesx402 pay-per-call: Get technology additions and removals for a domain$0.0495 USDC per call (x402, no account)
POST/agent/company-domainsx402 pay-per-call: Find domains associated with a company name$0.0495 USDC per call (x402, no account)
POST/agent/tagsx402 pay-per-call: Find related domains from an IP address or attribute$0.0495 USDC per call (x402, no account)
POST/agent/recommendationsx402 pay-per-call: Recommend technologies for a domain$0.0495 USDC per call (x402, no account)
POST/agent/redirectsx402 pay-per-call: Get live and historical redirects for a domain$0.0495 USDC per call (x402, no account)
POST/agent/keywordsx402 pay-per-call: Get keyword data for a domain$0.0495 USDC per call (x402, no account)
POST/agent/trustx402 pay-per-call: Get trust and risk signals for a domain$0.0495 USDC per call (x402, no account)
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