Answer engine

An answer engine is a search tool that replies to a question with a written answer, usually with cited sources, instead of a list of links. ChatGPT, Perplexity, Gemini, Microsoft Copilot, Claude and Google AI Mode are answer engines. Most combine a large language model with live web search.

Also called: Generative engine, AI search engine

Why answer engines matter

An answer engine changes where the shortlist is made. Instead of ten links to compare, the user reads one answer that names a few options. The audience is large: OpenAI says 1 billion people turn to ChatGPT every week, and Microsoft now calls Bing with Copilot Search "your AI-powered search and answer engine."

Researchers use the term generative engine. The 2023 paper that introduced generative engine optimization says these engines "typically satisfy queries by synthesizing information from multiple sources and summarizing them using LLMs." For a brand, the question moves from "do we rank?" to "are we named?", the shift described in AEO vs SEO.

The main answer engines

Each answer engine retrieves pages through its own search index or partners, so one prompt can name different brands in each.

ChatGPT

OpenAI's assistant. When a question needs current information, ChatGPT search rewrites it into queries for its search providers and cites the pages it uses. Sites must allow the OAI-SearchBot crawler to be shown in its search answers. Hawkscan tracks ChatGPT.

Perplexity

An AI search assistant that, when users ask a question, "might visit a web page to help provide an accurate answer and include a link to the page in its response." Its PerplexityBot crawler surfaces sites in Perplexity's results and is not used to train foundation models. Hawkscan does not track Perplexity.

Gemini

Google's AI assistant app, with 950 million monthly active users in the second quarter of 2026 according to Alphabet. The Gemini apps can ground answers in Google's Search index at prompt time, a use that site owners control with the Google-Extended token. Hawkscan tracks Gemini.

Microsoft Copilot

Microsoft's AI assistant. Microsoft says experiences like Copilot are powered by Bing's search index and handle billions of queries each month. Since April 2025, Copilot Search has also brought cited answers into Bing itself. Hawkscan tracks Microsoft Copilot.

Claude

Anthropic's AI assistant. Claude has been able to search the web since March 2025, with direct citations to its sources. Anthropic runs a separate crawler, Claude-SearchBot, to index content for search, apart from ClaudeBot, which collects training data. Hawkscan does not track Claude.

How to measure your brand in answer engines

Start with access: an engine can only cite pages it is allowed to retrieve. Allow OAI-SearchBot for ChatGPT, PerplexityBot for Perplexity and Claude-SearchBot for Claude, and keep the regular Google and Bing crawlers in for Gemini, Google AI Mode and Copilot.

Then measure. Answers vary from one engine to the next and from one run to the next, so a single check proves little. Pick the prompts your buyers ask, run them repeatedly on the engines they use, and read who gets named. Hawkscan shows the full answers from ChatGPT, Gemini, Microsoft Copilot and Google AI Mode for every prompt you track, with the brands named and the pages cited. It does not cover Perplexity or Claude: check those by hand.