Bananarr

Bananarr is a Chrome extension that tells you what a website is built with. Open a page, trigger the extension, and it inspects the site and lays out the technologies behind it, from the programming language and frameworks down to the CMS, the hosting provider, the analytics, and the payment tools. The tagline sums up the idea well, since it's about peeling back the tech stack of any website. It's the kind of thing developers, agency teams, and curious builders reach for when they land on a slick site and want to know how it was put together. Whether you're studying a competitor or just satisfying your curiosity, it answers the what-is-this-built-with question in a couple of seconds.

Tools that profile a site's technology have been around for years, but most of them work by sending the pages you visit off to a server so the vendor can analyze them, which quietly turns your browsing into someone else's data. Bananarr takes the opposite stance. The signature database ships inside the extension itself, so detection runs entirely on your own machine and nothing about the pages you look at leaves the browser. If you care about privacy, or you're poking at client sites you'd rather not report to a third party, that offline-first design is the whole point. It also means the extension keeps working the same way regardless of network conditions, since it isn't waiting on a remote API to hand back an answer before it can show you anything.

When it scans, Bananarr looks at a site from two angles at once. It reads the DOM selectors, scripts, links, images, cookies, and meta tags on the page, and it also checks the window globals the site exposes at runtime, which together give it a fuller picture than any single signal would. Every detection comes with the specific evidence that triggered it, so you're not staring at a bare list of guesses. You can see why it flagged React, or Shopify, or a particular analytics script, which makes it easy to trust a result or dig in further when something surprises you. That transparency is a real difference from tools that just print a verdict and expect you to believe it, since here the reasoning travels with every item in the list.

Results are organized into color-coded categories that cover the whole stack, including languages, backend and frontend frameworks, CSS tooling, CMS platforms, e-commerce, hosting, analytics, security, and payments. There's also a local IP range database that identifies the hosting provider behind a site, so it can tell you whether a page sits on AWS, Cloudflare, Fastly, Akamai, Google Cloud, or Azure without ever calling out to anyone. Scans finish in seconds, and a keyboard shortcut, Option plus B on Mac or Alt plus B on Windows, means you can check a site without ever leaving the page or reaching for the mouse. The categories keep a long detection list readable, so you can jump straight to the part of the stack you actually care about rather than scanning the whole thing.

The extension fits front-end developers sizing up how a competitor built something, agency and sales teams qualifying a prospect's stack before a pitch, security-minded folks auditing what a page quietly loads, and hobbyists who just like knowing what's under the hood. Because there's no account, no sign-up, and no quota, there's nothing to manage and nothing to log into. You install it and start scanning, and it works the same on the tenth site as it does on the first, with no usage meter counting down in the background. For a tool people tend to reach for many times a day, that lack of friction is a good part of why it's pleasant to keep around.

What makes Bananarr stand out in a crowded category is the combination of local detection and honest evidence. Plenty of profilers will hand you a list of technologies, but many of them phone home to do it, and few actually show their work. Bananarr keeps everything on your machine and attaches the reason behind each call, so you get both privacy and something you can verify for yourself. The two-world scanning approach also tends to catch things a page-only scan misses, since a lot of a site's real stack shows up in its runtime globals rather than in the markup you can view by hand. That's the sort of detail that separates a guess from a genuinely useful read on how a site was assembled.

Access is free. There are no paid tiers, no account, and no quotas to work around, so the cost of trying it is just the install. That does mean it's a focused, single-purpose tool rather than a dashboard with reporting, history, or team features, and detection quality naturally depends on the bundled signatures keeping pace with new frameworks as they appear. For a fast, private way to answer the question of what a site is built with, though, it does exactly what it says and then gets out of the way. If you've been leaning on a heavier profiler that tracks your browsing, this is a leaner and quieter alternative.