Framework Detection: a beginner's guide

A JavaScript framework is a library that imposes a structure for building interactive web applications, so developers don't have to reinvent every common pattern from scratch. The big names are React (Facebook, 2013), Vue.js (Evan You, 2014), Angular (Google, 2010), Svelte (Rich Harris, 2016), and Solid (Ryan Carniato, 2021). On top of those base frameworks sit meta-frameworks — Next.js (built on React), Nuxt (built on Vue), SvelteKit (built on Svelte), Remix (built on React) — which add server-side rendering, routing, data loading, and a hundred other features that turn a base framework into a complete application platform.

You should care because the framework choice is a strong signal of engineering culture and maturity. A team running Next.js has made deliberate choices about server-side rendering, SEO, and developer ergonomics. A team running plain HTML and jQuery is probably either very small, very legacy, or very deliberately minimal. A team running Angular is probably an enterprise team that values structure and TypeScript. None of these is better or worse — they are all valid — but they tell you what kind of team you are talking to. For sales, recruiting, integration planning, and competitive intelligence, the framework is one of the highest-signal facts you can learn.

The five things every framework detection check looks at:

• JavaScript globals. `window.React`, `window.Vue`, `window.Angular`, `window.__NEXT_DATA__`, `window.__NUXT__`, and so on.

• Distinctive HTML class patterns. React uses `data-reactroot`, Vue uses `data-v-*` attributes, and so on.

• Bundle file paths. `/static/js/main.*.js`, `/_next/static/`, `/_nuxt/`, `/.svelte-kit/` are all framework fingerprints.

• Response headers. `X-Powered-By: Next.js` is sometimes set; some hosting platforms also leak the framework in headers.

• Routing behavior. Single-page applications with client-side routing show characteristic patterns in how the URL changes during navigation.

Three questions a framework detection check answers:

• What JavaScript framework and meta-framework is this site built on?

• Is the team using a modern stack (React + Next.js, Vue + Nuxt) or a legacy one (jQuery, plain Angular 1.x)?

• For a recruiting pitch, can I tailor the conversation to their actual tech stack?

The cost of guessing the framework is leading every conversation with the wrong assumptions about the team. The fix is one detection pass per domain. The framework landscape moves fast, so the detection database needs to be kept up to date — but the most common frameworks have been stable enough that a basic check covers most of the web.

In one sentence: Detect frontend/backend frameworks

Identifies frontend and backend web frameworks used by a website. Detects React, Vue, Angular, Next.js, Django, Rails, Laravel, and many more.

Don't worry if some of the words above are still unfamiliar — there's a plain-language glossary at the bottom of this page, and most of the terms link to their own beginner guides if you want to learn more.

Here's what's actually happening behind the scenes when you call this endpoint:

Analyzes HTML (HyperText Markup Language) the structured form of an HTML page patterns (data attributes, inline markers), script source URLs, and HTTP (HyperText Transfer Protocol) response headers (X-Powered-By) to identify web frameworks. Covers frontend frameworks (React, Vue, Angular, Svelte, htmx, Alpine.js), meta-frameworks (Next.js, Nuxt, Remix, SvelteKit, Qwik), and backend frameworks (Rails, Django, Laravel, Express, FastAPI, Phoenix).

If you're using an AI assistant through MCP, you don't need to understand any of the technical details — the assistant calls the tool and translates the result for you.

Let's skip the marketing fluff and answer the only question that actually matters: why should you, a real human with a real to-do list, care about the Framework Detection tool? Here's the plain-English version, written the way you'd hear it from a friend who happens to do this for a living.

Framework identification helps developers understand technology choices, enables targeted security testing, and provides insights for competitive analysis and hiring decisions.

Picture this in real life. Imagine a CTO. Here's the situation they're walking into: Analyze competitor tech stacks to understand their development approach and capabilities. Without the right tool, that person would be stuck copy-pasting between five browser tabs, reading documentation written for engineers, and crossing their fingers that the answer they cobble together is correct. With the Framework Detection tool, the same person gets a clear answer in seconds — no spreadsheets, no guessing, no waiting for someone on the infrastructure team to free up.

Three questions this tool answers in plain English. If any of these have ever crossed your mind, the Framework Detection tool is built for you:

• What is this website actually built with, layer by layer?

• Who hosts it, who runs analytics on it, who delivers the assets?

• Is the company on a stack that fits my product, my pitch, or my integration?

You can either click the tool and get the answer yourself, or ask your AI assistant — connected through MCP (Model Context Protocol) — to ask the question for you and translate the answer into something you can paste into Slack.

Who gets the most out of this. Sales teams qualifying leads, marketers researching competitors, partnership managers scoping integrations, and security teams looking for known-vulnerable software in the wild. If you see yourself in that list, this is one of the EdgeDNS tools you should bookmark today.

What happens if you skip this entirely. Skip it and you're guessing at how a website is built — which kills sales calls, integration scoping, and competitive research. That's why running this check — even once a month — is one of the cheapest forms of insurance you can give your domain.

If you're still on the fence about whether the Framework Detection tool belongs in your toolbox, this section is for you. Below you'll meet three real people — a CTO, a security engineer, and a recruiter — facing three real situations where this tool turns a stressful afternoon into a five-minute task. Read whichever story sounds closest to your week.

Story 1: Competitive Tech Analysis

Imagine you're a CTO. Analyze competitor tech stacks to understand their development approach and capabilities.

Why it matters: Inform technology decisions based on competitor choices.

Story 2: Security Testing

Imagine you're a security engineer. Identify frameworks to focus on framework-specific vulnerabilities (e.g., Django admin exposure).

Why it matters: Efficient security testing with framework-aware approach.

Story 3: Talent Assessment

Imagine you're a recruiter. Identify companies using specific frameworks for targeted tech recruiting.

Why it matters: Find companies matching candidate expertise.

Common situations across teams. Beyond the three stories above, here are the everyday workplace moments when people across the company reach for the Framework Detection tool — or one of the tools right next to it in this category. If any of these are on your calendar this month, that's your sign:

• During sales prospecting, to qualify a lead by what they are running.

• During competitive research, to understand what a rival is built with.

• When scoping an integration or partnership.

• When you suspect a target is using a known-vulnerable version of something.

If you can see yourself in even one of those bullets, the Framework Detection tool will pay for itself the first time you use it.

Still not sure? Here's the easiest test in the world. Open Claude, ChatGPT, Gemini, or any other AI assistant connected to the EdgeDNS MCP server and ask, in your own words: "Is the Framework Detection tool useful for my job?" The assistant will look at the tool, ask you a couple of follow-up questions about what you're trying to accomplish, and give you a straight answer in plain English. No commitment, no signup forms, no jargon.

If you've connected the EdgeDNS MCP server to Claude, ChatGPT, Gemini, Cursor, or any other AI assistant, you don't need to write any code. Just ask in plain English:

"Use the Framework Detection tool to check vercel.com and explain anything that looks wrong in plain language."

The AI will figure out which tool to call, fill in the right parameters, run it, and then explain the result back to you. No copy-pasting between tabs. No reading raw JSON. No memorizing endpoint names.

If you're a developer and want to call the endpoint from a script or your own application, here's the simplest possible example. Replace the placeholder API key with the real one from your dashboard.

There's just one piece of information you need to provide. The table below explains exactly what it is and what a real value looks like.

When you call this tool, you'll get back a JSON object with the fields below. If you're talking to it through an AI assistant, the assistant reads these for you and explains them in plain language — you don't need to memorize them.

These tools pair naturally with Framework Detection. If you're already running this check, the related ones often answer the next question that comes up:

• Technology Detection — Detect frameworks, CMS, and libraries

• CMS Detection — Identify CMS, plugins, themes, and page builders

• Analytics Detection — Find tracking and analytics tools

If you're using an AI assistant through MCP (Model Context Protocol), you can ask it to run several of these in one go: "Check Framework Detection and the related tools for example.com and tell me what looks off."

If any words on this page felt like jargon, here's a plain-language version. Click any linked term to read a full beginner-friendly guide.

HTTP (HyperText Transfer Protocol) — The language web browsers and websites use to talk to each other.

HTML (HyperText Markup Language) — The basic language web pages are written in. The tags you see in the source code (<h1>, <p>, <a>) are HTML.