WhatRuns vs Wappalyzer vs StackPeek: Best Technology Detection Tool (2026)

You want to know what technologies a website uses. Maybe you're qualifying sales leads, scoping a competitor's stack, or building a tool that needs tech detection baked in. Three names keep coming up: WhatRuns, Wappalyzer, and StackPeek.

All three detect website technologies. But they're built for completely different workflows. WhatRuns is a free browser extension with no API. Wappalyzer is a well-known extension backed by a paid API at enterprise pricing. StackPeek is an API-first tool built for developers who need fast, affordable, automated detection.

This guide breaks down exactly where each tool wins, where it falls short, and which one fits your use case — so you stop wasting time on tools that don't match your workflow.

Quick Comparison: WhatRuns vs Wappalyzer vs StackPeek

WhatRuns: The Free Manual Lookup Tool

WhatRuns is a free browser extension that lets you check the technology stack of any website you're visiting. Click the icon in your toolbar, and it shows you the frameworks, fonts, analytics tools, and CMS the page uses. It's simple, it's free, and it does exactly one thing.

What WhatRuns does well

• Completely free: No paid plans, no usage limits on the extension. You can check as many sites as you want, one at a time, in your browser.
• Low friction: Install the extension, click the icon, see results. No sign-up, no API key, no configuration.
• Decent coverage: Detects around 700 technologies including major frameworks, CMS platforms, analytics tools, and fonts.

Where WhatRuns falls short

• No API: This is the biggest limitation. If you need to check 100 websites programmatically, WhatRuns cannot help. Every lookup requires you to manually visit the site and click the extension.
• No automation: No webhooks, no batch processing, no integrations with CRMs or data pipelines. It is purely a manual tool.
• No export or bulk features: You cannot export results to CSV, feed them into a database, or trigger actions based on detected technologies.
• No confidence scores: WhatRuns doesn't tell you how confident it is in each detection. You get a binary list — either a technology is detected or it isn't.

WhatRuns is perfect if you occasionally want to see what a competitor's site runs on. But the moment you need to scale beyond manual lookups, you need something else.

Wappalyzer: The Established Player with Enterprise Pricing

Wappalyzer is the most recognized name in tech detection, thanks to its widely-installed browser extension. Under the hood, it maintains a fingerprint database of over 1,500 technologies spanning 90+ categories — from JavaScript frameworks and CMS plugins to marketing tools and payment processors.

What Wappalyzer does well

• Largest fingerprint database: 1,500+ technologies with granular categorization. Detects specific WordPress plugins, Shopify themes, and niche JavaScript libraries that smaller databases miss.
• Polished browser extension: Available on Chrome, Firefox, and Edge. Clean UI with category grouping.
• Full API: Unlike WhatRuns, Wappalyzer offers a real REST API for automated lookups, bulk processing, and integration with CRMs and data pipelines.
• CRM integrations: Enrich leads in HubSpot, Salesforce, and other tools with technology data.

Where Wappalyzer falls short

• API pricing: Starts at $250/month. For startups and indie developers, this is a significant expense just for technology detection.
• API speed: 2–5 second response times because it relies on headless browser rendering to detect client-side technologies. Fine for batch jobs, painful for real-time UIs.
• Free tier is tiny: Only 50 lookups per month on the free plan. Enough to test, not enough to build on.

Wappalyzer is the right choice if you need the deepest detection database and your budget supports enterprise pricing. But for developers building products that need tech detection as a feature, $250/month is a steep cost for a single API dependency.

StackPeek: The API-First WhatRuns Alternative

StackPeek approaches tech detection differently. Instead of trying to catalog every technology ever written, it focuses on the 120+ technologies that drive business decisions — the frameworks, CMSs, hosting providers, CDNs, analytics platforms, and payment processors that sales teams, developers, and product managers actually care about.

What StackPeek does well

• Speed: Sub-500ms API responses. No headless browser — detection runs against HTTP headers, HTML source, script fingerprints, and meta tags. Fast enough for real-time UIs.
• Price: $9/month for 5,000 scans. That's 28x cheaper than Wappalyzer for API access. The free tier gives you 100 scans per day with no API key required.
• Developer-first: Clean JSON responses with confidence scores. No SDK needed — just a GET request. Works from any language, any platform.
• Focused database: 120+ technologies sounds small compared to Wappalyzer's 1,500+, but it covers every major framework (React, Next.js, Vue, Angular, Nuxt, Svelte), CMS (WordPress, Shopify, Squarespace, Wix), hosting provider (Vercel, Netlify, AWS, Cloudflare), analytics tool (GA4, Plausible, Hotjar), and payment processor (Stripe, PayPal). These are the technologies that actually matter for lead qualification, competitive analysis, and technology auditing.

StackPeek pricing

Head-to-Head: API Pricing for 5,000 Scans/Month

This is where the difference gets real. If you need to scan 5,000 websites per month — a common volume for SaaS features, internal tools, and lead enrichment workflows — here's what you'd pay:

StackPeek is 28x cheaper than Wappalyzer and delivers results 5–10x faster. WhatRuns doesn't even enter the conversation here because it has no API at all. If your use case requires programmatic access, WhatRuns is off the table entirely.

Use Cases: Which Tool Fits Your Workflow?

Manual competitor research

You want to see what a handful of competitor websites run on. You'll do this a few times a week, always from your browser.

Best tool: WhatRuns. It's free, it's fast for one-off checks, and you don't need to sign up for anything. Wappalyzer's extension works too, but WhatRuns is simpler.

Lead generation and sales intelligence at scale

You're building prospect lists. You need to scan 1,000+ websites to find which ones run Shopify, HubSpot, or WordPress, then feed that data into your CRM.

Best tool: StackPeek. At $9/month for 5,000 scans, you can qualify leads at scale without enterprise pricing. Wappalyzer can do this too, but at $250/month the unit economics only make sense at high volumes with high contract values. WhatRuns cannot do this at all.

Building tech detection into your own product

You're a developer building a SaaS that shows users the tech stack of any URL. You need a fast, reliable API you can call from your backend.

Best tool: StackPeek. Sub-500ms responses mean your users aren't waiting. The free tier lets you prototype and ship without paying anything. And at $9/month for production, it won't eat your margin.

Security auditing and vulnerability scanning

You need to identify outdated frameworks, known-vulnerable CMS versions, or specific technologies with open CVEs.

Best tool: Wappalyzer or StackPeek depending on depth. If you need to detect specific plugin versions, Wappalyzer's 1,500+ database is more thorough. If you need to scan fast and check for major frameworks, StackPeek's speed and pricing win.

Enriching CRM contacts with tech data

You want to automatically tag leads in HubSpot or Salesforce with the technologies their company uses.

Best tool: Wappalyzer if you need native CRM integrations out of the box. StackPeek if you're building a custom integration and care about API cost. WhatRuns cannot do this.

Detection Accuracy: An Honest Look

Wappalyzer detects 1,500+ technologies. StackPeek detects 120+. WhatRuns detects around 700. Does that make Wappalyzer 12x better than StackPeek?

Not for most use cases. The difference is in the long tail. Wappalyzer will tell you which specific WordPress plugin a site uses for contact forms, or identify an obscure A/B testing library with 200 installs. StackPeek focuses on the technologies that actually drive business decisions: the CMS, the framework, the hosting provider, the CDN, the analytics platform, and the payment processor.

For lead qualification, knowing that a site runs WordPress on AWS with Stripe is all you need. You don't need to know which WordPress caching plugin they chose. For competitive analysis, knowing the framework and hosting is what matters. For developer tooling, the core 120 covers the technologies your users care about.

StackPeek's fingerprint database is also growing weekly. New technology signatures are added based on user requests and market trends. The goal is not to catalog everything — it's to detect the technologies that matter with high confidence and low latency.

The Bottom Line

WhatRuns is a solid free tool for casual browsing. If you only need to check what a website runs on once in a while, and you always do it from your browser, WhatRuns is fine. But it has no API, no automation, and no path to scaling beyond manual clicks.

Wappalyzer is the established player with the largest fingerprint database and the broadest feature set. If you need 1,500+ technology detection, CRM integrations, and have the budget for $250/month API access, Wappalyzer delivers.

StackPeek is the best WhatRuns alternative for developers and teams that need API access without enterprise pricing. At $9/month — 28x cheaper than Wappalyzer — with sub-500ms responses and a generous free tier, it's built for the people who actually need to integrate tech detection into their products and workflows.

Stop paying enterprise prices for a single API dependency. Stop doing manual lookups when you need automation. Pick the tool that matches your actual workflow.

See StackPeek pricing →  |  Read the API docs →