Documentation
How Fathom collects traffic data, what it measures, and how to connect a site.
Fathom is web analytics measured at the Cloudflare edge. Instead of relying only on a script that runs in a visitor's browser, it records every request that reaches a site's Cloudflare zone, which is what lets it see crawlers, AI agents, errors and cache behavior that a browser beacon never sees.
What Fathom measures
For each site you get:
- Visitors and pageviews. Pageviews are successful, non-bot page requests; static assets, API calls and WordPress admin traffic are excluded. The site header, Top Pages and Top Referrers all use this one definition.
- Bots and AI agents by name. Machine traffic is classified against a registry of crawler signatures, so GPTBot, ClaudeBot, Googlebot and the rest appear by name with what they fetched and the bandwidth they used.
- Errors. 4xx and 5xx responses per page, from the edge log.
- Search performance. With Google Search Console connected, impressions and clicks sit next to the pages that actually received visitors, and the insights feed flags the gaps.
Raw request data is kept for 90 days. Per-minute aggregates are kept for twelve months. Visitor addresses are hashed with a salt that rotates every day before anything is stored.
Getting started
Follow Connect your first site.
What is not measured without Cloudflare
A site that only has the JavaScript snippet installed still reports visitors and pageviews. It cannot report bots, AI agents, error rates or cache behavior, because those come from the edge request log. The dashboard says "not measured" for those numbers rather than showing a zero.