Best Free Website Technology Checker Tools in 2026
You're about to hop on a sales call. You pull up the prospect's website and wonder: What CMS are they using? Do they have a chatbot? What analytics platform? Are they running HubSpot or Salesforce?
Or maybe you're a developer scoping a competitor's site, a marketer evaluating a potential partner, or a founder doing due diligence.
Whatever the reason, knowing what technology a website uses is incredibly valuable — and there are free tools that can tell you in seconds.
We tested 10 of the most popular website technology checker tools in 2026 and ranked them on accuracy, depth, speed, and actual free-tier usability. Here's what we found.
Why Check a Website's Technology Stack?
Before diving into tools, here's why this matters:
- Sales prospecting: If you sell a Shopify app and a prospect runs WooCommerce, you're wasting your time. Tech stack data lets you qualify leads instantly.
- Competitive intelligence: See what tools your competitors use for analytics, A/B testing, live chat, and marketing automation.
- Development scoping: Evaluate what frameworks, CDNs, and hosting providers a site relies on before building an integration.
- M&A due diligence: Understand technical debt and infrastructure before acquiring a company.
- Partnership evaluation: Check if a potential partner uses compatible technology before proposing an integration.
According to a 2025 Gartner report, the average mid-market company uses 120+ SaaS tools. That's a lot of technology surface area to analyze — and manual inspection won't cut it.
How Website Technology Checkers Work
Most tech stack detection tools use a combination of these methods:
- HTTP header analysis — Server headers reveal web servers (Nginx, Apache), frameworks, and caching layers.
- JavaScript library detection — Scanning the DOM for known JavaScript frameworks, analytics scripts, and tracking pixels.
- DNS and SSL analysis — DNS records and SSL certificates can reveal hosting providers and CDN usage.
- HTML meta tag scanning — CMS platforms often leave fingerprints in meta tags, generator tags, and structured data.
- Cookie analysis — Different platforms set distinctive cookies that can be identified.
- Pattern matching — Comparing page source code against databases of thousands of known technology signatures.
The best tools combine multiple methods to maximize detection accuracy.
The 10 Best Free Website Technology Checker Tools
1. MarketBetter Tech Stack Detector (Best Overall Free Option)
Website: tools.marketbetter.ai/techstack-detector
What it does: Enter any URL and get a comprehensive breakdown of the technologies that site uses — CMS, frameworks, analytics, marketing tools, hosting, CDN, and more.
Why it stands out:
- Completely free — no signup required, no credit card, no usage limits for individual lookups
- AI-enhanced detection — goes beyond pattern matching to identify technologies that other tools miss
- Sales-focused output — results are organized in a way that's immediately useful for prospecting (e.g., "this company uses HubSpot for marketing automation" rather than just listing script names)
- Clean, fast interface — paste a URL, get results in under 10 seconds
- No browser extension required — works entirely in the browser
Limitations: Designed for individual URL lookups rather than bulk scanning. For analyzing thousands of URLs at once, you'd pair this with a programmatic tool.
Best for: Sales reps who need quick tech stack intel before calls, marketers doing competitive research, and anyone who wants accurate results without creating an account.
2. BuiltWith
Website: builtwith.com
What it does: One of the original technology profiling tools. Enter a URL and get a detailed breakdown organized by category (analytics, frameworks, CDN, hosting, CMS, etc.).
Pricing:
- Free: Individual URL lookups with basic results
- Basic: $295/month (full technology lists, lead generation features)
- Pro: $495/month (extended historical data)
- Enterprise: $995/month (API access, bulk lookups)
Pros:
- Massive technology database (tracks 100,000+ technologies)
- Historical data showing when technologies were added or removed
- Market share data for each technology category
- Lead lists filtered by technology (paid feature)
Cons:
- Free tier shows limited results — many technologies are hidden behind the paywall
- Interface feels dated compared to newer tools
- Expensive if you need full data access
- Can be slow on complex sites
Best for: Enterprise teams with budget for deep technographic data and lead list building.
3. Wappalyzer
Website: wappalyzer.com
What it does: Browser extension and web-based tool that identifies technologies on websites. Originally open-source, now a commercial product owned by Dun & Bradstreet.
Pricing:
- Free: Browser extension with basic detection (50 lookups/month)
- Starter: $99/month (1,000 lookups)
- Team: $249/month (5,000 lookups)
- Business: $449/month (10,000 lookups)
- Enterprise: Custom pricing
Pros:
- Browser extension works passively as you browse — see tech stacks without leaving the page
- Well-organized categories (67+ technology categories)
- API available for programmatic access
- Company and contact data bundled in paid plans
Cons:
- Free tier is very limited (50 lookups/month)
- Was open-source, now fully commercial — some community resentment
- Browser extension can slow page loading
- Accuracy has declined according to some users after the acquisition
Best for: Users who want passive tech detection while browsing and are willing to pay for API access.
4. WhatRuns
Website: whatruns.com
What it does: Browser extension that shows the technologies used by any website you visit. Focuses on simplicity.
Pricing: Free (with optional paid plans for teams)
Pros:
- Genuinely free browser extension
- Simple, clean interface
- Detects WordPress themes and plugins specifically
- Works on any page you visit
Cons:
- Chrome extension only — no web-based lookup
- Detection accuracy is lower than BuiltWith or Wappalyzer for less common technologies
- Limited to what can be detected client-side
- No API or bulk scanning capabilities
Best for: Casual users who want a free browser extension for quick checks.
5. Stackcrawler
Website: stackcrawler.com
What it does: Web-based technology checker with a focus on CMS and e-commerce platform detection (particularly strong at identifying Shopify stores).
Pricing: Free for individual lookups
Pros:
- Good at e-commerce platform detection (Shopify, WooCommerce, Magento)
- Clean, modern interface
- No signup required
- Includes some hosting and CDN detection
Cons:
- Narrower technology coverage than BuiltWith or Wappalyzer
- E-commerce focus means it may miss SaaS tools, marketing tech, and analytics
- No bulk scanning
- Limited to major technology categories
Best for: E-commerce professionals who primarily need CMS and platform detection.
6. W3Techs
Website: w3techs.com/sites
What it does: Academic-grade technology survey tool. Enter a URL to check specific technology categories, or browse their extensive market share reports.
Pricing: Free for site lookups; premium reports available
Pros:
- Extremely accurate for server-side technologies (web servers, programming languages, CMS)
- Trusted by researchers — their methodology is transparent and well-documented
- Market share data updated daily
- No account required
Cons:
- Doesn't detect client-side technologies well (JavaScript frameworks, analytics, marketing tools)
- Interface is functional but not pretty
- Focused on top-level technologies, not granular MarTech detection
- No API for programmatic access
Best for: Developers and researchers who need reliable server-side technology data.
7. Hexomatic Tech Stack Analyzer
Website: hexomatic.com/tools/tech-stack-analyzer
What it does: Free tool that detects technologies used on any website, with results organized by category.
Pricing: Free tool (part of Hexomatic's automation platform; paid plans start at $20/month)
Pros:
- Detects 1,000+ technologies
- Free to use without signup
- Can be combined with Hexomatic's automation workflows for bulk scanning
- Decent accuracy for common technologies
Cons:
- Free tool shows basic results; advanced features require a Hexomatic subscription
- Slower than dedicated tech stack tools
- Part of a broader platform — not a focused tech detection product
- Detection database isn't as comprehensive as BuiltWith
Best for: Users already on Hexomatic's platform who want to add tech detection to their automation workflows.
8. Seomator Website Technology Checker
Website: seomator.com/website-technology-checker
What it does: Free technology lookup as part of Seomator's SEO audit platform.
Pricing: Free for individual lookups
Pros:
- No signup required
- Combines tech stack data with SEO audit information
- Decent at detecting CMS, JavaScript libraries, and analytics tools
Cons:
- Limited technology database
- Primarily an SEO tool — tech detection is a secondary feature
- Results can be incomplete for non-web-standard technologies
- No bulk or API access
Best for: SEO professionals who want tech stack data as part of a broader site audit.
9. WhatCMS
Website: whatcms.org
What it does: Focused tool for detecting Content Management Systems. Also identifies hosting providers and some web technologies.
Pricing: Free for individual lookups; API plans from $10/month
Pros:
- Best-in-class CMS detection (identifies 800+ CMS platforms)
- Also detects WordPress themes and plugins
- API available at reasonable prices
- Fast and accurate for its focus area
Cons:
- CMS-focused — doesn't detect most MarTech, analytics, or development frameworks
- Not useful if you need a full technology profile
- Limited free API calls (10/day)
Best for: Agencies and developers who primarily need to identify CMS platforms.
10. Ful.io
Website: ful.io
What it does: Technology detection with a Chrome extension and web-based lookup. Includes contact information discovery.
Pricing: Free tier available; paid plans for team features
Pros:
- Combines tech detection with contact info discovery
- Chrome extension for passive detection
- Includes e-commerce platform identification
Cons:
- Newer tool with smaller technology database
- Free tier has usage limits
- Accuracy varies depending on the technology category
- Less established reputation
Best for: Users who want tech detection and contact data in one tool.
Quick Comparison Table
| Tool | Free Tier | Technologies Detected | Signup Required | Bulk Scan | API |
|---|---|---|---|---|---|
| MarketBetter | ✅ Unlimited individual lookups | 500+ | No | No | No |
| BuiltWith | ✅ Limited results | 100,000+ | No | Paid | Paid ($295+/mo) |
| Wappalyzer | ✅ 50/month | 3,000+ | Yes | Paid | Paid ($99+/mo) |
| WhatRuns | ✅ Free extension | 1,000+ | No | No | No |
| Stackcrawler | ✅ Unlimited | 500+ | No | No | No |
| W3Techs | ✅ Free | Server-side focused | No | No | No |
| Hexomatic | ✅ Free tool | 1,000+ | No | Paid | Paid |
| Seomator | ✅ Free | 300+ | No | No | No |
| WhatCMS | ✅ Limited | CMS-focused (800+) | No | API only | $10/mo |
| Ful.io | ✅ Limited | 1,000+ | Yes | No | No |
How to Use Tech Stack Data for Sales Prospecting
Knowing what tools a website uses is only valuable if you act on it. Here's the playbook:
1. Qualify Leads by Technology Fit
If you sell a Salesforce integration, check if prospects actually use Salesforce before reaching out. This alone can double your reply rates by eliminating bad-fit prospects.
2. Personalize Your Outreach
"I noticed you're running HubSpot with a WordPress site" is a dramatically better opening line than "Hi, I'd like to tell you about our product." Tech stack data makes personalization effortless.
3. Identify Competitive Displacement Opportunities
If a prospect uses a competitor's product, you know exactly what to position against. "I see you're on Marketo — here's how teams like yours have saved 40% by switching" hits harder than a generic pitch.
4. Build Targeted Account Lists
Filter your total addressable market by technology to create hyper-focused lists. Companies using Shopify + Klaviyo + Google Analytics represent a very different buyer than those using Magento + Salesforce + Adobe Analytics.
5. Trigger Event-Based Outreach
If you can detect when a company adds or removes a technology, that's a buying signal. Company just added Drift? They're investing in conversational marketing and might be open to related tools.
When to Use Which Tool
- Quick individual lookups (no signup): MarketBetter Tech Stack Detector — paste a URL, get results instantly
- Passive browsing detection: WhatRuns (free Chrome extension)
- Enterprise technographic data: BuiltWith (if you have the budget)
- Programmatic/API access: Wappalyzer or WhatCMS
- CMS-specific detection: WhatCMS
- E-commerce platform focus: Stackcrawler
- Server-side technology research: W3Techs
The Bottom Line
For most users — especially sales reps, marketers, and founders — the best website technology checker is the one that gives you accurate results without friction. You shouldn't need to create an account, install an extension, or pay $295/month just to see what CMS a website uses.
MarketBetter's Tech Stack Detector does exactly that: paste any URL, get a comprehensive tech stack breakdown in seconds, completely free. No signup, no limits for individual lookups, no hidden paywalls.
Try it now — pick any website you're curious about and see what it's built with.
Looking for more free tools? Check out our AI Lead Generator to find buyer contacts at any company, or use the Lookalike Company Finder to discover companies similar to your best customers.