GEO guides
These GEO guides explain how AI search finds and cites pages, from the crawlers that collect them to the searches ChatGPT, Claude and Gemini run, and each one points you to the free tool that checks it.
Common Crawl guides
Common Crawl guides explain the open web archive that many AI training sets start from, and the bot that fills it.
What is Common Crawl?
What Common Crawl is, how its monthly crawls work, who funds it, and how to search it for your own site.
CCBot: Common Crawl's web crawler
CCBot is Common Crawl's web crawler: its user agent, how it reads robots.txt, and why a firewall can block it when robots.txt says yes.
How the Common Crawl checker works
How the Common Crawl checker reads the crawl index from your browser, and what each result means.
AI search engine and crawler guides
These AI search engine and crawler guides show which index each assistant reads and which crawlers it sends to your site.
What search engine does ChatGPT use?
Which search engine ChatGPT uses (Bing, reported Google results and OpenAI's own crawler), and what ChatGPT actually searches for.
What search engine does Claude use?
Which search engine Claude uses, Brave Search, the evidence for it, and how Claude's own crawlers fit in.
OAI-SearchBot: the crawler behind ChatGPT search
OAI-SearchBot is the crawler behind ChatGPT search: how it differs from GPTBot and ChatGPT-User, and the robots.txt rules to use.
Cloudflare AI Crawl Control: is it blocking AI crawlers on your site?
Whether Cloudflare AI Crawl Control is blocking AI crawlers on your site, what changed on September 15, 2026, and how to check.
GEO audit and tool guides
These GEO audit and tool guides cover checking a site end to end, the tools that help, and the reports search engines now give you.
AI visibility audit: a 7-step GEO audit you can run free
An AI visibility audit in seven free steps, from robots.txt and firewalls to the searches AI runs and where you rank for them.
Best GEO tools: generative engine optimization tools for every job
The best GEO tools sorted by job, free and paid, with what each generative engine optimization tool measures and costs.
Bing Webmaster Tools AI Performance report: how to read it
How to read the Bing Webmaster Tools AI Performance report: citations, grounding queries, intents and citation share.
GEO research
Our GEO research publishes the data behind these guides, starting with 100 prompts run through ChatGPT, Claude and Gemini.
Fan-out queries: what ChatGPT, Claude and Gemini actually search
Fan-out queries from 100 prompts run through ChatGPT, Claude and Gemini: how many searches each runs, what repeats and what they search for.