# Method

Each homepage was loaded in a rendering browser in September 2026 and matched against Installmap's fingerprint rules with `scrapers/detect.py`. The base for each list is every homepage that returned a page we could score: 5,388 Y Combinator companies, 4,888 Inc. 5000 (2026) companies, 1,000 unicorns and 472 Fortune 500 companies.

PostHog counts when the page calls `posthog.init(` with a project key or loads a script from a `*.i.posthog.com` or `app.posthog.com` host. The other tools count from their own tracking script fingerprints.

The count is what the homepage loads on a first visit with no consent given. Tags that fire only after a consent click, or only inside the product, are not seen, so every count is a lower bound. PostHog is often installed in the app rather than on the marketing site, which makes it more of a lower bound than most.