Wappalyzer vs WhatRuns: Which Tech Detection Tool Should You Use?

Wappalyzer and WhatRuns are two of the most popular browser extensions for identifying what technologies a website uses. Both let you click a button and see a list of frameworks, CMSs, analytics tools, and more. But underneath that shared premise, they take very different approaches.

This post compares both tools honestly—features, limitations, and pricing—so you can pick the right one for your workflow. We'll also cover what to do if you need API access or detection capabilities that go beyond what browser extensions offer.

What They Have in Common

Both Wappalyzer and WhatRuns are browser extensions available for Chrome and Firefox. They both:

• Detect technologies on any website you visit
• Show results as a popup when you click the extension icon
• Categorize detected technologies (CMS, JavaScript frameworks, analytics, hosting, etc.)
• Offer a free browser extension

That's roughly where the similarities end. The differences matter, especially if you need tech detection beyond casual manual lookups.

Key Differences

Wappalyzer

Wappalyzer started as an open-source project in 2009 and has grown into a commercial product. It was acquired by Sindup in August 2023, and the open-source repository was archived. The underlying fingerprint database (6,000+ technology signatures) is still maintained, and the extension remains free.

Beyond the browser extension, Wappalyzer offers paid API access starting at $250/month, with the Business plan at $450/month. It also provides CRM integrations (HubSpot, Salesforce, Pipedrive), lead list generation, and bulk lookup tools.

WhatRuns

WhatRuns is a free browser extension focused solely on manual tech detection. There is no API, no paid plans, no open-source codebase, and no bulk analysis features. You install it, click the icon on any site, and see what it detects. That's the entire product.

WhatRuns does offer a "follow" feature that notifies you when a site changes its tech stack, which is a useful touch for competitive monitoring without any code.

Feature Comparison

When to Use Wappalyzer

Wappalyzer is the better choice when you need more than a browser extension:

• API access: If you need to detect technologies programmatically—in a script, pipeline, or application—Wappalyzer has a REST API. WhatRuns does not.
• Bulk analysis: Need to scan hundreds or thousands of sites? Wappalyzer's API and bulk lookup tools handle this. With WhatRuns, you'd have to click through each site manually.
• CRM/sales workflows: If you're enriching leads with tech stack data in HubSpot or Salesforce, Wappalyzer has native integrations.
• Open-source fingerprints: While the official repo is archived, the Wappalyzer fingerprint format is widely used. Many community forks and tools (including DetectZeStack) build on Wappalyzer's signature patterns.
• Enterprise features: Lead list generation, team management, and usage dashboards are available on paid plans.

When to Use WhatRuns

WhatRuns is the better choice for simpler use cases:

• Quick manual checks: If you just want to know what a site is built with while you're browsing, WhatRuns does the job with zero cost and zero setup.
• Completely free: WhatRuns has no paid tier. There's no upsell, no trial expiration, no feature gating. The full product is free.
• Tech change monitoring: The "follow" feature lets you track when sites you care about change their stack—without writing any code or paying for webhooks.
• No API needed: If your workflow is entirely manual (e.g., researching competitors before a pitch), WhatRuns is simpler and lighter than Wappalyzer's extension.

What Neither Tool Does

Both Wappalyzer and WhatRuns detect technologies by analyzing HTTP responses and HTML content in the browser. This approach works well for frontend technologies, but it misses an entire layer of infrastructure that isn't visible in the page source:

• DNS-based detection: CDN providers (Cloudflare, Fastly, Akamai) and hosting platforms often reveal themselves through DNS CNAME records. Browser extensions can't query DNS.
• TLS certificate inspection: The certificate authority and certificate details can identify hosting providers and security infrastructure. Browser extensions don't expose this data.
• CPE identifiers: Neither tool maps detected technologies to CPE (Common Platform Enumeration) identifiers, which are used to cross-reference the NVD vulnerability database.

If you need any of these capabilities, you'll need a server-side detection tool rather than a browser extension.

Need an API Without the Enterprise Price?

If you're comparing Wappalyzer and WhatRuns because you need tech detection for a project, there's a good chance you'll eventually outgrow what a browser extension offers. The jump to Wappalyzer's API at $250+/month is steep if you're an indie developer, a startup, or running a side project.

DetectZeStack is a REST API built for developers who need programmatic tech detection at a reasonable price:

• Free tier: 100 requests/month with full API access. No credit card required.
• $9/month: 1,000 requests/month. Full API access, same endpoints, no feature gating.
• DNS + TLS detection: Server-side analysis that catches CDN providers, hosting infrastructure, and certificate authorities that browser extensions miss entirely.
• CPE identifiers: Detected technologies include CPE identifiers (when available) for mapping to vulnerability databases—something neither Wappalyzer nor WhatRuns provides.
• Batch analysis: Scan up to 10 URLs in a single API call.
• Stack comparison: The /compare endpoint shows shared and unique technologies across multiple sites.

curl -s "https://detectzestack.com/analyze?url=example.com" \
  -H "X-Api-Key: YOUR_KEY" | jq '.technologies[].name'

See how it compares: DetectZeStack vs Wappalyzer | DetectZeStack vs WhatRuns | DetectZeStack vs BuiltWith

The Verdict