Why does it not detect the chat widget / heatmap / pixel I know the site uses?

Almost certainly because a tag manager injects it after the page loads. This tool reads the served response, and anything added by JavaScript afterwards is invisible to it. The report's Not Checked section states this rather than letting the gap read as absence.

Can a site block this kind of detection?

Largely, yes. Removing generator tags, stripping identifying headers and self-hosting assets removes most fingerprints. That is why an empty report is a fact about the response, not proof of an empty stack.

Is the detected version the version actually running?

It is the version the response declares, which is not the same thing. Headers can be frozen by configuration or set to mislead. For inventory purposes it is usually right; for security decisions it is not evidence either way.

Why is there no score on this report?

Because an inventory has nothing to score. A stack is not better for being detectable, and grading technology choices from one fetch would be exactly the kind of invented judgement these tools are built to avoid.

Why does it say Next.js but not React?

Next.js is a React framework, so listing both would be padding the count. The framework is reported because it is the more specific, more useful fact. React appears on its own only when no React-based framework was identified.

Does checking a site notify or affect it?

One ordinary GET request is made — the same as a visitor loading the page once. Nothing is stored, and nothing is probed beyond the page you name.

Website Technology Checker

Identifies what a website is built with — CMS, framework, server, CDN, analytics — from the response it actually serves, with the evidence and a confidence level for every detection.

What is this website built with?

Reads the served page and reports every technology it can identify, with the evidence for each.

Need this as an API?

Why use it

Built to be genuinely useful

Every detection shows its working

Expand any entry to see the exact header, tag or script URL it was identified from, quoted verbatim. Nothing is asserted without something to point at.

Three honest confidence levels

Certain means the site names it — a generator tag, an X-Powered-By header. High means a pattern that in practice belongs to one technology. Possible means consistent but imitable. The badge tells you which claim you are reading.

Versions only when declared

A version number appears only when the response states one — nginx/1.24.0, ng-version, a jquery-3.7.1 filename. No version is ever inferred from a pattern, because a guess wearing a number is worse than an honest blank.

Absence stated, not implied

Categories where nothing was found are listed as quiet, alongside why that is not proof — hidden stacks and script-injected tools are invisible to a single fetch, and the report says so.

How it works

Three steps

1
Enter a website address. One request is made and the served response is read.
2
Detections are grouped — platform, framework, server, CDN, analytics — each with its confidence badge.
3
Expand any entry for the evidence; read the Not Checked section for what one fetch cannot see.

How technology detection actually works

Websites leak what they are built with, mostly through laziness rather than intent. A CMS writes a generator tag because that is the default. A server announces itself in the Server header. A framework leaves its hydration payload in the page. A theme loads its scripts from paths that name the platform. Detection is nothing more exotic than reading these and knowing which belong to what.

The consequence worth understanding: detection quality depends entirely on what the site chooses to send. A default WordPress install is identifiable four different ways; a hardened one behind a strict proxy may be identifiable zero ways. The confidence ladder exists because these are different situations and a tool that reports both as flat facts is flattening exactly the distinction that matters.

That is also why absence proves nothing. A report with an empty language row does not mean the site has no backend language. It means the backend declined to introduce itself, which well-run sites deliberately do.

What each confidence level licenses you to conclude

Certain detections are quotes. The response said WordPress 6.5, or nginx/1.24.0, or ng-version 17.3.1, and the only way the conclusion is wrong is if the site is deliberately lying — which happens, occasionally, precisely to confuse tools like this one.

High-confidence detections rest on patterns with essentially one real-world source: /wp-content/ paths, a __NEXT_DATA__ payload, a cf-ray header. Treat them as reliable, while remembering they are inference rather than declaration.

Possible detections are the honest bottom rung. Utility-class naming that looks like Tailwind, a cookie name shared by two frameworks. They are included because they are genuinely informative and labelled because acting on them as certainties is how wrong migration plans get written.

What people actually use this for

Competitor research is the obvious one: what platform do the sites you admire run, and what analytics stack do they trust. It is also the fast way to answer the internal question nobody wrote down — what is our own site actually running, after years of agencies, plugins and migrations.

It earns its keep before commissioning work. A proposal to rebuild your site means something different depending on whether the current one is WordPress, Webflow or a custom Next.js build, and knowing which before the first call keeps the conversation concrete.

One caution: version numbers in headers are useful for inventory and famous for being stale. A frozen Server header can survive years of upgrades behind it. Treat a declared version as what the site says, not as an audit of what is installed — and if you are checking your own site, the interesting question is usually why it is disclosing versions at all, which the Security Headers Checker covers from the defensive side.

FAQ

Questions people ask

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