If you sell a Shopify app, a HubSpot alternative or a Stripe integration, your best prospects are easy to describe: companies that already run a particular tool . The data that tells you who they are is called technographics . Most tools sell it as a subscription; this post shows a pay-per-result way to get the same kind of list in Python.

What "websites using X" data actually is

Crawlers fetch home pages and fingerprint the scripts, headers and HTML they find (the same idea as Wappalyzer). Each domain gets a list of detected technologies plus metadata: country, language, title and a "last seen" date. Two things follow from that:

Only front-end-visible tools show up.…