WhatStack

See what any website is built with — frameworks, tools, and libraries. Instant, private stack detection.

WhatStack tells you what a website is built with — instantly, on the page you’re already viewing. Open any site, click the toolbar icon, and get a clear breakdown of its frontend stack. No DevTools digging, no guesswork from the marketing page, no account. WHY INSTALL IT • Research competitors and products — learn real stacks, not job-post fluff • Speed up technical interviews, sales calls, and client discovery • Learn by example — see how production sites actually ship • Share findings with your team as text, Markdown, or JSON • Stay private — detection runs only on your device; nothing is uploaded WHAT YOU GET • A one-line summary of the core stack, for example “Next.js · React · Webpack” • Results grouped by category, each with a confidence level (high, medium or low), so weak signals never look like facts • The evidence behind every result — expand a row to see exactly what was matched on the page • A toolbar badge that shows how many technologies were found as you browse WHAT IT RECOGNIZES More than 80 technologies across twelve categories: frameworks, CMS and site builders, micro-frontend architecture, build tools, state management, data fetching and routing, UI and CSS libraries, authentication, payments, error monitoring, analytics, and hosting. WhatStack only counts real evidence — scripts the page actually loads, objects running on the page, and markers in its structure. Words on the page, file names and search terms never count. Some heavily minified sites leave no fingerprints, so a missing result does not always mean a tool is absent. BUILT FOR TRUST Everything runs on your machine. WhatStack does not upload page content or results, does not sell data, and has no ads. If a result looks wrong, the “Wrong?” button opens a draft GitHub issue that you review and submit yourself — it includes the site’s origin only, never the full URL. HOW TO USE 1. Install WhatStack 2. Visit any website 3. Click the WhatStack icon 4. Read the summary and the categories 5. Optional: copy the results or report a miss Single purpose: identify the frontend technology stack of the web page you are viewing.