How to Find Out What Technologies a Website Uses (Framework, CMS, CDN)

You see a website with a design or feature you like and wonder what it's built with: WordPress with a custom theme? Next.js? Shopify? Finding this out doesn't require asking the developer for access: most web technologies leave detectable fingerprints in the HTML, HTTP headers and resources the page loads.

How a website's technology is detected without code access

A site built with a specific technology usually leaves identifiable signals, even when the source code isn't directly visible:

• HTML patterns: WordPress generates very characteristic CSS classes and file paths (/wp-content/, /wp-includes/); Next.js includes scripts with recognizable names (_next/static/).
• HTTP headers: some servers and CDNs identify themselves directly in the Server header or in custom headers (Cloudflare, for example, adds specific, easily recognizable headers).
• Scripts and external resources: the presence of certain analytics scripts, chat widgets or JavaScript frameworks reveals what tools the site uses.
• Generator metadata: some CMSs include a <meta name="generator"> tag with the exact name and version.

How to detect a website's technology

1. Enter the URL you want to analyze.
2. The tool examines the HTML, headers and loaded resources.
3. Review the detected framework, CMS, CDN, server and analytics tools.

You can do it free with the tech stack detector on this site.

What this is actually useful for

• Competitive research: understanding what technology a competitor's or industry-reference site is built with.
• Evaluating a provider or freelancer: before hiring someone to maintain a site, knowing what stack it was built with helps assess whether the new team has experience with that technology.
• Detecting third-party services: seeing what CDN, analytics or live chat a site uses, useful for drawing inspiration from tools used by reference sites.
• Legitimate technical curiosity: simply understanding how a site that caught your eye is built.

The limits of this detection

Not every technology leaves equally clear fingerprints. A well-configured backend can deliberately hide its Server header, and certain rendering techniques (aggressive server-side rendering, obfuscated CSS classes) can make detecting the exact frontend framework harder. What gets detected is what the site publicly exposes to the browser, not an audit of the actual source code.

Frequently asked questions

Does this access the site's private source code? No, it only analyzes what any browser publicly receives when loading the page: HTML, headers and resources.

Is the detection 100% accurate? Not always; some technologies deliberately hide themselves or leave ambiguous signals, so the result is a reliable estimate, not an absolute certainty.

Can I use this to tell if a site uses WordPress? Yes, it's one of the easiest cases to detect due to its characteristic file paths and classes.

Does it detect exact software versions? Sometimes, when the site exposes that information in metadata or headers; not always possible if the site hides it.

Discover what technologies any website uses for free with the tech stack detector, analyzing framework, CMS, CDN and analytics in seconds.