Claude

Claude is the LLM family from Anthropic, a company founded by former OpenAI researchers with an explicit focus on safer, more interpretable AI. The lineage runs from Claude 1 and 2 through Claude 3, 3.5 and 4. While ChatGPT leads in consumer mindshare, Claude has steadily climbed in enterprise, developer and coding tool environments, where its behaviour profile fits production work especially well.

Technically, Claude leans heavily on Constitutional AI for alignment. Instead of relying solely on human labellers ranking outputs, the model critiques and revises its own responses against a written set of principles. The practical result is a model that tends to be measured, citation-friendly and unusually capable with long contexts — Claude variants routinely handle 200K to a million tokens of input without falling apart.

Claude matters to marketers for two reasons. First, it is embedded far beyond its own chat product. It powers Claude Code, internal enterprise assistants and a great deal of API-driven automation, so users may rely on Claude indirectly through other SaaS and developer tools without ever opening claude.ai. Second, Claude's training data and citation behaviour differ from ChatGPT's, which means it picks different sources for the same query. GEO measurement that ignores Claude is measuring a single brand half the time.

A common misread is that Claude is just an OpenAI alternative. In practice the two behave quite differently across answer length, citation format, refusal policies, coding quality and Korean handling. Claude tends to outperform on long-document analysis — manuals, contracts, research — while GPT-4o-class models often feel snappier on fast multimodal chat. Treating 'LLM' as synonymous with ChatGPT will quietly hide the entire Claude-using audience from your GEO data.

Operationally, Anthropic publishes its crawler behaviour (ClaudeBot and related agents) more transparently than most. That makes the GEO checklist for getting into Claude's citation pool — robots.txt, llms.txt, sitemaps, structured data — unusually concrete. The emerging standard for serious GEO programs is dual tracking: measure citation share inside both ChatGPT and Claude, and use the gap between them to diagnose which surface needs work first.