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Answer engines compared

From AEO.wiki, the Answer Engine Optimization reference · Last reviewed · By · Published by Local Blitz · How we research

Each answer engine retrieves from a different place: Google's AI features and Gemini from Google's index, Copilot from Bing, ChatGPT from OAI-SearchBot plus search partners, Perplexity from its own crawler plus live search, and Claude (according to reporting) from Brave Search. Allow each engine's search crawler, rank in the index it uses, and measure where the vendor gives you data.

Comparison table

EngineWhere answers come fromSearch crawler / controlTraining controlPublisher reporting
Google AI Overviews & AI ModeGoogle Search index, RAG and query fan-out[1]Googlebot; Search Console generative AI control; nosnippet and noindex[2][3]Google-Extended (not used for Search)[4]Search Console Generative AI performance report[5]
ChatGPT searchOAI-SearchBot index plus third-party search providers[6][7]OAI-SearchBot; ChatGPT-User for user-triggered visits[6]GPTBot[6]None; utm_source=chatgpt.com on referrals[8]
PerplexityReal-time web search with citations[9]PerplexityBot; Perplexity-User for user fetches[10]PerplexityBot is not used for training, per Perplexity[10]None documented
Microsoft CopilotBing index and grounding[11]Bingbot; NOCACHE and NOARCHIVE affect Copilot use[11]Not separately documented in the guidelinesBing Webmaster Tools AI Performance[12]
Gemini app & APIGrounding with Google Search[13]Googlebot crawling; Google-Extended governs Gemini grounding[4]Google-Extended[4]None for the Gemini app
ClaudeWeb search tool; TechCrunch reported Brave Search as the provider[14][15]Claude-SearchBot; Claude-User for user fetches[16]ClaudeBot[16]None documented
Voice assistantsVendor search plus LLM partners (for example Siri and ChatGPT)[17]Applebot for Siri and Spotlight[18]Applebot-Extended[18]None

Each cell is taken from the vendor’s own documentation unless it names a news report. “None” means we found no publisher-facing report as of September 2026.

What this means in practice

  1. Be in both big indexes. Google’s index feeds AI Overviews, AI Mode and Gemini grounding. Bing’s index feeds Copilot, and OpenAI lists Microsoft among ChatGPT’s search providers.[7] Verify the site in Search Console and Bing Webmaster Tools.
  2. Allow the search crawlers you want to be cited by. OAI-SearchBot, PerplexityBot and Claude-SearchBot are separate from the training crawlers. Blocking a search crawler removes you from that engine’s answers: OpenAI says opted-out sites “will not be shown in ChatGPT search answers.”[6] Use the robots.txt builder.
  3. Check your CDN. Google’s guide says to make sure crawling is allowed “by any CDN or hosting infrastructure”,[3] and Cloudflare began blocking AI crawlers by default on new domains in July 2025.[19]
  4. Measure what you can. Google and Bing now report AI impressions and citations; other engines only show up as referral traffic (see AI traffic in GA4).

Accuracy varies by engine

In the Tow Center’s 2025 test of eight AI search tools, Perplexity answered 37% of queries incorrectly and Grok 3 answered 94% incorrectly; the tools collectively got more than 60% wrong.[20] Monitor how each engine describes your brand, not just whether it links to you.

References

Pages accessed September 28, 2026 unless a date is given. See all sources and our editorial policy.

  1. ^ "Optimizing your website for generative AI features on Google Search". Google Search Central. Added May 15, 2026; last updated July 10, 2026.
  2. ^ "Search generative AI control". Search Console Help. Rolled out to all sites by August 31, 2026.
  3. ^ "AI features and your website". Google Search Central. Last updated December 10, 2025.
  4. ^ "Google’s common crawlers (including Google-Extended)". Google Search Central. Last updated July 14, 2026.
  5. ^ "Generative AI performance report (Search)". Search Console Help. Rolled out to all sites by August 31, 2026.
  6. ^ "Overview of OpenAI Crawlers". OpenAI Platform documentation.
  7. ^ "Searching the web with ChatGPT". OpenAI Help Center.
  8. ^ "Publishers and Developers – FAQ". OpenAI Help Center.
  9. ^ "What is Perplexity?". Perplexity Help Center.
  10. ^ "Perplexity Crawlers". Perplexity documentation.
  11. ^ "Bing Webmaster Guidelines". Microsoft Bing Webmaster Tools.
  12. ^ "Introducing AI Performance in Bing Webmaster Tools Public Preview". Bing Webmaster Blog. Published February 10, 2026.
  13. ^ "Grounding with Google Search (Gemini API)". Google AI for Developers.
  14. ^ "Web search tool". Claude Platform documentation.
  15. ^ "Anthropic appears to be using Brave to power web search for its Claude chatbot". TechCrunch. Published March 21, 2025.
  16. ^ "Does Anthropic crawl data from the web, and how can site owners block the crawler?". Anthropic (Claude Help Center).
  17. ^ "Apple Intelligence now features Image Playground, Genmoji, Writing Tools enhancements, seamless support for ChatGPT, and visual intelligence". Apple Newsroom. Published December 11, 2024.
  18. ^ "About Applebot (including Applebot-Extended)". Apple Support.
  19. ^ "Content Independence Day: no AI crawl without compensation!". Cloudflare Blog. Published July 1, 2025.
  20. ^ "AI Search Has a Citation Problem (Jaźwińska and Chandrasekar)". Columbia Journalism Review, Tow Center for Digital Journalism. Published March 6, 2025.
Categories: Answer engines