What is Answer Engine Optimization (AEO)?

Answer Engine Optimization (AEO) is the practice of structuring your brand, content, and data so that AI search engines like ChatGPT, Perplexity, Claude, Gemini, and Google AI Overviews cite you as the answer. Unlike traditional SEO, AEO targets generative answers rather than ranked blue links.

How does Hertz help my brand appear in ChatGPT and Perplexity?

Hertz tracks every prompt where your category is discussed, measures your share of AI mentions across ChatGPT, Perplexity, Claude, Gemini, Grok, Copilot, and Google AI Overviews, and gives you a prioritized list of content, schema, and entity fixes so AI engines cite your brand as the answer.

What is the difference between SEO and AEO?

SEO optimizes for ranked search results on Google and Bing. AEO optimizes for the generated answers produced by AI engines such as ChatGPT, Perplexity, and Google AI Overviews. AEO uses entity clarity, structured data, and quotable, factual content so AI engines pick your brand when they answer a user.

Which AI search engines does Hertz monitor?

Hertz monitors ChatGPT, Perplexity, Claude, Gemini, Google AI Overviews, Google AI Mode, Grok, and Microsoft Copilot. You see your visibility, sentiment, and share of voice on each engine in one dashboard.

How much does Hertz cost?

Hertz Starter is £149/month, Growth is £299/month, and Enterprise is custom-priced. Every plan includes a 7-day free trial and tracks all six major AI search engines.

How long does AEO take to work?

Most Hertz customers see measurable changes in AI mentions within 2–4 weeks of implementing prioritized fixes, because AI engines re-crawl and re-index content far more frequently than traditional Google rankings update.

Engines · 7 min · 2026-06-20

AI Answer Engines: The Complete List for 2026

The major engines

ChatGPT — OpenAI's flagship, the largest active user base and the broadest tool ecosystem.
Google AI Overviews — generated answers at the top of Google search, the highest-volume answer surface in the world.
Gemini — Google's standalone assistant, deeply integrated with Workspace and Android.
Perplexity — research-first engine known for transparent citations and aggressive freshness.
Microsoft Copilot — embedded across Bing, Windows and Microsoft 365, strong in enterprise contexts.
Claude — Anthropic's assistant, popular for long-form research and increasingly for in-product agents.
Grok — xAI's engine, tightly integrated with X and weighted toward real-time discussion.

Challengers and specialists

DuckDuckGo AI Chat — privacy-focused frontend that routes to multiple models.
You.com — multi-model assistant with research and coding modes.
Brave Leo — privacy-first assistant inside the Brave browser.
Kagi Assistant — paid search engine's assistant layer, popular with power users.
Arc Search — browser-native answers from The Browser Company.
Mistral Le Chat — European challenger with growing enterprise traction.

Why the list keeps changing

The composition of the top tier is stable, but ranking inside it shifts each quarter as models release, retrieval indices update and product surfaces change. AI Overviews, for example, became the highest-volume answer surface in the world almost overnight when Google rolled it out to a wider set of queries.

Underneath the top tier, dozens of category-specific assistants are gaining share — coding assistants, legal research engines, medical Q&A tools. For brands operating in those verticals, the vertical assistant often matters more than the generalist engines.

How to prioritise coverage

Start with the engines your buyers actually use. For most B2B that is ChatGPT, Perplexity and increasingly AI Overviews. For consumer it skews toward AI Overviews, Gemini and ChatGPT. For developer-tooling brands, Claude and Copilot punch above their weight.

Once the top three engines for your audience are instrumented, expand outward. The marginal cost of adding another engine to a prompt-tracking programme is small, and the diversification protects you from single-engine model regressions.

Frequently asked questions

How many engines should I track?

Most mature AEO programmes track between five and ten engines. Fewer than five risks blind spots; more than ten adds noise without proportional insight.

Are AI Overviews and Gemini the same thing?

No. AI Overviews are generated answers inside Google search results. Gemini is Google's standalone assistant. They share underlying models but behave differently and cite differently.

Do new engines launch often?

Major engines launch once or twice a year. Specialist and vertical engines launch monthly. Continuous monitoring is the only way to keep coverage current.

AI Answer Engines: The Complete List for 2026