BuiltWith vs WhatRuns: Enterprise Data vs Free Extension (2026)

BuiltWith and WhatRuns both detect what technologies a website uses, but they could not be more different. BuiltWith is an enterprise SaaS platform priced from $295 to $995+ per month with a massive crawled database. WhatRuns is a free browser extension that analyzes pages in real time as you visit them.

If you're trying to decide between the two, the answer depends entirely on what you need: enterprise-scale data and lead generation, or quick manual lookups at zero cost. In this post, we'll break down exactly what each tool offers, where each falls short, and what to consider if neither is quite right.

Key Differences at a Glance

Before diving into details, here's the fundamental distinction: BuiltWith crawls millions of websites on a schedule and builds a searchable database. WhatRuns analyzes a single page live when you visit it in your browser. They serve different use cases entirely.

• BuiltWith is built for sales teams, market researchers, and enterprises that need to answer questions like "Which Shopify stores use Klaviyo?" across millions of domains. It's a data product.
• WhatRuns is built for individuals who want to right-click a website and see what it's running. It's a utility tool.

Feature Comparison

BuiltWith: The Enterprise Database

BuiltWith has been around since 2007 and has built the largest technology detection database in the industry—over 111,000 technology signatures. It periodically crawls millions of websites and stores the results in a searchable database with historical snapshots going back years.

Strengths

• Massive technology database: ~111,000 signatures covering everything from major frameworks to obscure analytics snippets, advertising pixels, and WordPress plugins.
• Lead lists: Filter domains by technology to build prospect lists. For example, find all sites using Magento in the US with more than 10,000 monthly visitors.
• Historical data: See when a website adopted or dropped a technology. Useful for tracking competitor migrations or market trends.
• Market share reports: Aggregate data on technology adoption across the web. Useful for market research and competitive analysis.
• API access: Available on the Pro plan ($995/mo) for programmatic queries against the crawled database.

Weaknesses

• Expensive: Plans range from $295/mo (Basic) to $995/mo (Pro). Enterprise plans go higher. There is no free tier for API access.
• Stale data: Because BuiltWith crawls periodically rather than on-demand, results can be days or weeks behind the current state of a website.
• No real-time analysis: You cannot point BuiltWith at a URL and get a live scan. It reports what its crawler found during the last pass.
• No infrastructure detection: BuiltWith focuses on HTTP/HTML fingerprinting. It does not inspect DNS records or TLS certificates, so it misses CDN providers, hosting infrastructure, and certificate authorities.

WhatRuns: The Free Extension

WhatRuns is a free browser extension for Chrome and Firefox. You install it, visit a website, click the extension icon, and it shows you what technologies that page uses. It performs its analysis live in your browser, which means results are always current.

Strengths

• Completely free: No cost, no account required. Install the extension and start using it immediately.
• Real-time analysis: Because it runs in your browser on the live page, you always see the current state of a site's technology stack.
• Zero friction: No API keys, no sign-up forms, no pricing pages. Just a browser extension that works.
• Follow notifications: You can "follow" a website and get notified when its technology stack changes.

Weaknesses

• No API: WhatRuns is browser-only. There is no API, no programmatic access, and no way to integrate it into automated workflows.
• Manual only: You have to visit each website individually. There is no bulk analysis, no batch processing, and no way to scan a list of domains.
• Smaller database: WhatRuns detects fewer technologies than BuiltWith's 111,000-signature database.
• No historical data: No archive of past technology usage. You only see what's on the page right now.
• No lead generation: No way to search for domains by technology. You can only analyze sites you already know about.
• Browser-dependent: Only works in Chrome and Firefox. Cannot run on a server, in a CI pipeline, or in any headless environment.

When to Choose BuiltWith

BuiltWith makes sense if you need features that only a large crawled database can provide:

• You need lead lists filtered by technology (e.g., "all Shopify stores using Stripe").
• You need historical data to track when competitors changed their stack.
• You need market share reports for investor decks or strategic planning.
• You have an enterprise budget that supports $295–$995/month.
• You need API access to query a pre-crawled database without waiting for live scans.

When to Choose WhatRuns

WhatRuns makes sense when your needs are simple and manual:

• You just need quick manual checks on sites you're visiting anyway.
• You have zero budget for tech detection tooling.
• You do not need an API or any form of automation.
• You check a handful of sites per week, not hundreds or thousands.
• You want real-time results without worrying about stale crawl data.

The Gap Between Them

The problem is obvious: there's a massive gap between "free but manual and browser-only" and "$295–$995/month enterprise SaaS." If you need an API but can't justify enterprise pricing, neither tool works. If you need automation but WhatRuns is your only option, you're stuck copying results by hand.

Neither tool provides DNS or TLS-based detection (identifying CDNs, hosting providers, and certificate authorities from infrastructure signals). And neither maps detected technologies to CPE identifiers for vulnerability tracking.

The Best of Both Worlds: DetectZeStack

DetectZeStack sits in the gap between these two extremes. It provides API access like BuiltWith—but starting at $9/month instead of $995/month. And it provides real-time analysis like WhatRuns—but via a REST API you can integrate into any workflow.

DetectZeStack combines HTTP and HTML fingerprinting with DNS CNAME analysis and TLS certificate inspection. This multi-layer approach catches infrastructure details—CDN providers, hosting platforms, certificate authorities—that neither BuiltWith nor WhatRuns detect.

Detected technologies include CPE identifiers (when available) that you can use to check for known vulnerabilities in the NVD, making DetectZeStack particularly useful for security teams and compliance workflows.

The Verdict

For most developers and small teams, the choice comes down to what you actually need. If it's lead lists, BuiltWith is unmatched. If it's free manual checks, WhatRuns works fine. If it's an affordable API with real-time detection, DetectZeStack fills the gap.

See also: BuiltWith vs Wappalyzer vs DetectZeStack and our Wappalyzer alternative page.