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How-To April 7, 2026 8 min read

How to See What Tech Stack a Website Uses

Every website leaves fingerprints — if you know where to look. Here's a practical guide to identifying the technology behind any site, from the front-end framework down to the analytics layer.

You land on a competitor's site. It's fast, the checkout flow is slick, and their personalization feels eerily accurate. A natural question forms: what are they actually running under the hood? Maybe you're evaluating vendors for your own stack, doing due diligence before a partnership, or simply trying to reverse-engineer what's making a rival successful. Whatever the reason, knowing how to identify a website's technology is one of the most useful skills in modern business.

The good news: most of a website's tech stack is detectable without any special access. JavaScript bundles, HTTP response headers, HTML meta tags, cookie names, script src attributes, and DNS records all leak information about the tools powering a site. The question is just how to read those signals efficiently.

What "Tech Stack" Actually Means

When people ask how to see what tech stack a website uses, they're usually asking about several overlapping layers:

A complete picture of a company's stack tells you a lot: how technically sophisticated they are, where they're investing budget, and what switching costs or integrations you'd be navigating in a partnership or competitive context.

Method 1: Inspect the Page Source

The simplest starting point is right-click → "View Page Source" in any browser. You're looking for a few things:

Script Tags

Script src attributes are goldmines. cdn.segment.com tells you they use Segment. js.hs-scripts.com means HubSpot. connect.facebook.net/en_US/fbevents.js is the Meta Pixel. Once you know the common patterns, you can spot them in seconds — but it takes practice and a mental library of hundreds of vendor signatures.

Meta Tags and Generator Hints

Many CMSs leave traces in the <head>. WordPress sites often include <meta name="generator" content="WordPress 6.x">. Squarespace and Wix both embed identifiable markup. Look for wp-content in image paths or static1.squarespace.com as an asset host.

Cookie Names

Open DevTools → Application → Cookies. HubSpot sets hubspotutk. Intercom uses intercom-session-*. Salesforce Marketing Cloud leaves _sfmc_id_. These cookies are hard to hide because they're set client-side to track users across sessions.

Most of a website's technology stack is visible to anyone who knows where to look. The challenge isn't access — it's signal-to-noise ratio.

Method 2: Read HTTP Response Headers

Open DevTools → Network tab, reload the page, click on the main document request, and look at the Response Headers. You'll often find:

Some stacks are deliberately obscured — security-conscious engineering teams strip revealing headers. But most sites don't bother, and even when they try, other signals compensate.

Method 3: Use a Website Technology Checker

Manually reading source and headers works, but it's slow and error-prone. For any kind of systematic research — competitive analysis, prospecting, due diligence — you need a website technology checker that automates detection.

This is exactly what SaaS Detective was built for. Install the Chrome extension, navigate to any website, and click the icon. Within a second you get a categorized breakdown of every detectable technology on the page — from the JavaScript framework and CMS to the marketing automation platform, analytics suite, payment processor, and chat widget.

Practical Tip

When using SaaS Detective to research a competitor, check multiple pages — not just the homepage. Product pages often load different analytics or A/B testing tools. Checkout pages reveal payment processors. Support pages expose live chat and ticketing systems. A full picture requires a few clicks across the site.

SaaS Detective covers 200+ technology signatures across 30+ categories. That means it's not just catching the obvious (WordPress, Shopify) — it's also identifying niche tools like specific heatmap vendors, server-side tag managers, consent management platforms, and subscription billing engines that manual inspection would miss entirely.

Method 4: DNS and WHOIS Lookups

Some infrastructure signals live in DNS records rather than the browser. A CNAME record pointing to *.hubspot.com reveals HubSpot hosting. Records pointing to *.netlify.app, *.vercel.app, or *.github.io tell you about their deployment setup. Services like MXToolbox or simply running dig / nslookup from a terminal surface these records in seconds.

Email-related DNS records (MX and TXT) also reveal marketing infrastructure. include:_spf.google.com in an SPF record confirms Google Workspace. include:servers.mcsv.net is Mailchimp. include:sendgrid.net is, obviously, SendGrid. These aren't always in scope for a tech stack question, but for sales and partnership research they're valuable.

Method 5: Third-Party Intelligence Tools

Beyond browser-based detection, there are platforms that crawl the web at scale and build databases of technology usage. BuiltWith and SimilarTech index millions of sites and let you query by technology — useful for market research ("how many Shopify stores in the US use Klaviyo?") but overkill for ad-hoc lookups. They're also expensive and gated behind paywalls.

For most use cases — sales research, competitive intel, client audits — a fast browser extension like SaaS Detective is the right tool. You get instant results on the specific site you're visiting without navigating to a separate platform, entering a URL, and waiting for a crawl.

What You Can and Can't Detect

It's worth being honest about limitations. Client-side detection picks up anything that runs in the browser. Server-side tools that never touch the front-end are invisible from the outside — internal databases, server-to-server APIs, backend languages, and microservices infrastructure won't show up in any browser-based check.

Similarly, some companies deliberately obfuscate their stack. They'll proxy third-party scripts through their own domain (first-party data collection), strip or spoof headers, and avoid loading client-side SDKs for tools that have server-side modes. This is increasingly common among privacy-forward companies and those running sophisticated ad fraud prevention.

That said, even a partially detected stack is enormously useful. Knowing someone runs HubSpot and Intercom on the front-end, even if you can't see their data warehouse, tells you a lot about their customer lifecycle tooling philosophy — and that's usually what matters for competitive research or sales preparation.

A partially detected stack still tells a compelling story. The tools a company chooses to run client-side reflect their priorities, budget, and technical sophistication.

Reading the Signals: What Stacks Say About Companies

Once you can reliably detect tech stacks, the next skill is interpretation. A few patterns worth knowing:

These patterns aren't universal, but they're directionally accurate often enough to be useful in sales conversations, competitive positioning, and vendor selection research.

Bottom Line

Figuring out what tech stack a website uses doesn't require insider access or expensive platforms. Between page source inspection, HTTP headers, cookie analysis, DNS lookups, and a browser extension like SaaS Detective, you can build an accurate picture of almost any site's technology in under five minutes. The manual methods teach you the underlying signals; the automated tools make the process fast enough to use every day. Start with SaaS Detective for routine lookups and dig into the raw signals when something unexpected shows up — or doesn't show up — in the results.

See It for Yourself

SaaS Detective reveals any website's full tech stack in one click. Free to install, no account required.

Add to Chrome — It's Free →