Competitor Tech Checker — Find Any Competitor's Stack

Paste a competitor's URL. See every framework, CMS, analytics tool, CDN, ad network, and A/B testing platform in their stack. Free, instant, no signup.

Try: airbnb.com · notion.so · figma.com · linear.app

Why Check a Competitor's Tech Stack?

Five reasons B2B teams pull this data weekly. The tool is free; the API behind it powers sales, product, and security workflows.

Sales prospecting

Find companies using a complementary tool (e.g., a Shopify store + no analytics) and pitch yours. Spray-and-pray cold outreach gets replaced with stack-qualified leads.

Competitive intelligence

See exactly how a rival is built — which CMS, which CDN, which analytics, which A/B testing tool. Spot the differences between fast-growing competitors and slow ones.

Lead scoring

Enrich CRM records with stack data. Companies running 25+ marketing tools score higher than those running 3 — your AE knows where to focus.

Hiring research

Before you apply or interview, know what's actually in production. "We use React" in a job post; the stack checker shows whether the marketing site is Vue and Next.js.

Migration planning

Switching from WordPress to a headless CMS? Look at how 10 companies you admire built theirs. Patterns in headers, CDN choice, and edge-rendering signals are all visible.

Security review

Pair a stack lookup with CPE identifiers and you have an instant vulnerability surface map for any third-party site you depend on. Critical for vendor security reviews.

What You'll See

Every category we detect — most sites return 15–40 items. Top examples per category:

JavaScript frameworks

React, Vue, Next.js, Angular, Svelte, Nuxt

CMS

WordPress, Webflow, Contentful, Sanity, Ghost

Ecommerce

Shopify, WooCommerce, BigCommerce, Magento

Analytics

Google Analytics, Mixpanel, Amplitude, Plausible, Heap

CDN / hosting

Cloudflare, Fastly, Akamai, AWS, Vercel, Netlify

Ad networks

Google Ads, Facebook Pixel, LinkedIn Insight

A/B testing

Optimizely, VWO, AB Tasty, Google Optimize

Customer support

Intercom, Drift, Zendesk, HubSpot

Payment / billing

Stripe, Recurly, Chargebee, Paddle

Security headers + TLS

HSTS, CSP, issuer cert, version

Need This in Code? Use the API

Bulk lookups, CRM enrichment, scheduled scans — script it.

curl "https://detectzestack.com/analyze?url=notion.so" \
  | jq '.technologies[] | {name, categories}'

100 requests/month free on RapidAPI. Paid plans from $9/month for 1,000 requests. Full docs: OpenAPI spec.

Frequently Asked Questions

How do I check what technologies a competitor uses?

Paste their domain into the checker at the top of this page. It inspects HTTP headers, page source, DNS records, and TLS metadata to identify every framework, CMS, analytics platform, CDN, ad network, and other technology in their stack — typically 15–40 items per site.

Is this competitor tech checker free?

Yes — the on-page tool is free, no signup. For bulk competitor research or programmatic CRM enrichment, the DetectZeStack API has a free tier (100 req/mo) and paid plans from $9/mo.

Why would I want to know a competitor's tech stack?

Common B2B uses: sales prospecting (find companies using a complementary tool), competitive intelligence (see how rivals are built), lead scoring (enrich CRM by stack maturity), hiring research, and migration planning. See the section above for examples.

How is this different from BuiltWith or Wappalyzer?

Same kind of data — but with a free API tier (BuiltWith starts at $295/mo), DNS-level CDN detection that browser extensions miss, and CPE identifiers (when available) for vulnerability lookups. Compare directly: vs BuiltWith, vs Wappalyzer, vs WhatRuns.

Can I run this on many competitors at once?

The on-page tool handles one URL at a time. For batch lookups (up to 10 URLs per API call) or recurring monitoring with webhook alerts when a competitor's stack changes, use the API.

Will the competitor know I checked them?

No. The lookup runs from our server and looks like any other HTTP request. There's no notification to the site owner.

Enrich Your CRM with Tech Stack Data

100 free API requests per month. No credit card.

Get Free API Key

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