Wappalyzer is the other technographic source we keep on hand for stack-based targeting, alongside BuiltWith. It identifies the technologies running on any website: CRM, ecommerce platform, analytics, ad tech, payment tools, and the underlying frameworks behind them. It began as a browser extension for instant on-page lookups and grew into a full lead-generation suite with technology lists, email verification, firmographics, and an API. You query by a single stack or by combinations of tools, then export the matching companies with their contacts. When a client offer depends on a buyer running a specific tool, the lists become a precise fit signal. The bundled verification trims dead contacts before they enter a sequence and quietly burn a sending domain's reputation over time. We reach for Wappalyzer when a client's offer hinges on a stack and the budget favors a lighter technographic option. It is a situational pick, not a default, and the choice usually comes down to cost and the exact technologies in play for that ICP. From there the flow is familiar. We pull the tech-matched companies, verify the emails, then enrich and route everything through Clay before outreach runs, so the list is both clean and tightly fit to what the client actually sells.