Answer engine crawlers are the bots and user agents that fetch pages for AI search, retrieval, model improvement, or user-triggered browsing. They matter because access is the first gate in answer-engine visibility.
Short answer
Decide crawler access by purpose: ordinary search, AI search inclusion, user-triggered retrieval, and model-improvement use. Do not treat every AI crawler as the same policy decision.
Crawler policy table
| Crawler | Use | AEO note |
|---|---|---|
| Googlebot | Google Search crawling | Needed for ordinary Search and Search AI feature eligibility. |
| Google-Extended | Gemini/Vertex AI model-use control | Separate from Google Search crawling. |
| OAI-SearchBot | OpenAI search-related crawling | Evaluate for ChatGPT search visibility. |
| GPTBot | OpenAI model-improvement crawling | Separate from OAI-SearchBot. |
| ChatGPT-User | User-triggered access | Important for user-requested browsing and actions. |
| PerplexityBot | Perplexity crawling | Relevant for source visibility and citation testing. |
Operational rule
Robots.txt is only one layer. Hosting security, CDN bot protection, rate limits, and firewall rules can block a crawler even when robots.txt allows it. Always test the live URL with the user agents you care about.
How to use this page
Use this page as the operating reference for the topic, then follow the related tools and guides for implementation. The goal is to move from a vague AEO concept to a concrete publishing action: what to check, what to change, and what to measure after the change.
Implementation checklist
- Confirm the target page is crawlable and canonical.
- Write a direct answer near the top of the page.
- Use headings that map to real prompts.
- Add examples, tables, or checklists where the reader needs a decision.
- Link to glossary definitions and deeper guides.
- Track whether answer engines mention the brand, cite the exact URL, or cite a competitor.
Measurement plan
Run a small prompt panel before and after major changes. Record the engine, prompt, cited URL, citation surface, result type, and notes. A page that moves from no mention to domain mention is progress, but the stronger goal is exact URL citation for the claim the page actually supports.
Common misconceptions
AEO is not a single tag, file, or plugin. It is the combination of access, source clarity, structured writing, evidence, internal links, and measurement. A page can have schema and still be ignored if it does not answer a prompt clearly. A page can rank and still fail to be cited if the relevant passage is vague or unsupported.