AI answer engines now sit between people and the open web, and each one retrieves, summarises and cites sources in its own way. An AI answer engine is a search product that runs one or more web searches on a user's behalf, reads the results with a large language model and returns a written answer with links to the pages it used. This hub lists the main engines from official provider pages with the same fields for each: owner, where results come from, how citations are shown, ads, entry price and publisher controls. It is written for marketers, publishers, security and privacy teams, and anyone who needs a factual map of AI search before choosing a tool or deciding how their content should be used. Engines are listed alphabetically; order is never a ranking.
Last checked: 2026-11-15.
This is an independent reference page from NHI Mgmt Group based on public provider documentation; it is not sponsored or endorsed by any provider.
Key takeaways
- Retrieval comes first, writing second. Every engine on this page searches an index (its own or a partner's), selects passages, then asks a model to compose an answer with links back to those pages.
- Few engines run their own full web index. Brave states that every result comes from its own index; OpenAI says ChatGPT search may send queries to third-party providers such as Bing; Yahoo says Scout uses Microsoft Bing's grounding API.
- Ads have arrived inside answers. Google is scaling ads in AI Mode across more countries and launched multiturn ads in the US, and OpenAI announced an ads test for ChatGPT Free and Go users in the US in January 2026.
- Publisher controls are splitting by purpose. Search, training and grounding now have separate switches: OAI-SearchBot versus GPTBot, PerplexityBot versus Perplexity-User, Google-Extended, and Bing's new ai-training and ai-grounding preferences.
- Facts move monthly. Google merged AI Overviews and AI Mode in May 2026 and Microsoft's new grounding preferences take effect from 1 February 2027, so check dates against the official source before acting.
What is an AI answer engine?
A traditional search engine returns a ranked list of links. An answer engine returns a composed response, usually with inline citations, and invites follow-up questions in the same thread. The term covers dedicated products (Perplexity, Yahoo Scout), search modes inside a classic engine (Google AI Mode), chat assistants with a web tool (ChatGPT search, Microsoft Copilot) and paid or API-first services (Kagi, Brave's Answers API, You.com).
| Shape | How it is reached | Examples on this page |
|---|---|---|
| AI mode inside a search engine | A tab or box on the search results page | Google AI Mode |
| Chat assistant with web search | Chat app that decides when to search, or a search button | ChatGPT search, Microsoft Copilot |
| Dedicated answer engine | Its own site and apps, answer first | Perplexity, Yahoo Scout |
| Paid search with an assistant | Subscription search engine with an AI assistant | Kagi Search and Assistant |
| Search and answer APIs | Developer APIs used to ground other applications and agents | Brave Search API, You.com APIs |
As of 2026-11-15.
How AI search finds, ranks and cites sources
Providers publish only part of how their systems work, but the official documentation describes a common pipeline.
- Query understanding and fan-out: Google's Search Central documentation says AI Overviews and AI Mode may use "query fan-out", issuing multiple related searches across subtopics and data sources to build a response. Google first described the technique when it launched AI Mode in Labs on 5 March 2025.
- Retrieval from an index: the engine pulls candidate pages from a web index. Google requires a page to be indexed and eligible to be shown with a snippet before it can be a supporting link. Brave says its Search API draws on an index of more than 40 billion pages that it crawls and ranks itself.
- Selection and grounding: passages are chosen and handed to the model. Microsoft defines grounding as using content as input to help inform AI-generated responses, and says it is separate from indexing and ranking for traditional Bing results.
- Composition: a model writes the answer. Google names Gemini 3.5 Flash as the default model for AI Mode worldwide from 20 May 2026; Yahoo names Anthropic's Claude as the primary foundational model for Scout.
- Citation: links are attached inline, in a sources panel or both. OpenAI describes inline citations plus a Sources button; Google said in October 2026 that inline links will appear higher in AI Mode and AI Overviews responses more often.
- Fallback: Google's help centre says AI Mode may show a set of web links instead of an AI response when confidence is not high enough.
On ranking, Google states there are no additional requirements to appear in AI Overviews or AI Mode and no special schema.org markup or AI-specific file is needed; standard SEO practice applies. No provider on this page publishes a full ranking formula for which sources are cited.
Which AI answer engines exist in 2026?
| Engine | Owner | Type | Where results come from | Model named by provider | Status (as of 2026-11-15) |
|---|---|---|---|---|---|
| Brave Search and Ask Brave | Brave Software | Search engine with AI answers; Search and Answers APIs | Brave's own independent index; no fallback to another engine | Not stated by Brave on the API page | Active |
| ChatGPT search | OpenAI | Web search inside ChatGPT | Disassociated queries may be sent to third-party providers such as Bing | Not stated by OpenAI on the search help page | Active |
| Google AI Mode (AI Search) | AI mode inside Google Search, merged with AI Overviews | Google Search index, Knowledge Graph, real-time and shopping data | Gemini 3.5 Flash named as default from 20 May 2026; help centre now lists Gemini 4 Hydrogen and Gemini 4 Carbon | Active | |
| Kagi Search and Assistant | Kagi | Paid ad-free search with an AI assistant | Not stated by Kagi on the pricing page | Several third-party models listed on the Ultimate plan | Active |
| Microsoft Copilot (consumer) | Microsoft | AI assistant that searches the web | Bing web grounding | Not stated by Microsoft on the product page | Active |
| Perplexity | Perplexity AI | Dedicated answer engine, Comet browser assistant | Not stated by Perplexity on the plans page; PerplexityBot crawls to surface and link sites | Automatic on Free; advanced models on paid plans | Active |
| Yahoo Scout | Yahoo | Dedicated answer engine | Microsoft Bing's grounding API plus Yahoo data and content | Claude (Anthropic) as primary model | Beta, US (launched 27 January 2026) |
| You.com | You.com | Search and answer APIs for developers and enterprises | Not stated by You.com on the homepage | Open-weight models via its Inference Router | Active; homepage presents APIs and enterprise products |
What does each engine offer?
Each profile uses the same fields. Prices are as published on the provider page on the check date, in US dollars, before tax.
Brave Search and Ask Brave
- Retrieval: Brave states that "every result comes from Brave's own independent index, crawled and ranked by Brave", and that no query falls back to another search engine.
- Citations: the Answers API grounds responses in one or more searches and supports citations and streaming.
- Price: Search API $5 per 1,000 requests with $5 of free credits each month; Answers API $4 per 1,000 requests plus $5 per million input and output tokens; Enterprise on custom terms.
- Ads in answers: Not stated by Brave on the API page.
ChatGPT search
- Retrieval: OpenAI says ChatGPT may send disassociated search queries to third-party providers such as Bing, and may share general location derived from the IP address with those providers.
- Citations: inline citations that can be previewed or opened, and a Sources button listing cited sources and other relevant links. See ChatGPT Search Explained.
- Price: available inside ChatGPT plans. See AI Chatbot Free Plans Compared.
- Ads in answers: OpenAI announced on 16 January 2026 a test of ads for logged-in adults in the US on Free and Go; it says Plus, Pro, Business and Enterprise will not include ads and that ads do not influence answers.
Google AI Mode
- Retrieval: query fan-out across Google Search. Google merged AI Overviews and AI Mode into one AI Search experience worldwide on 20 May 2026 and reports more than 1 billion monthly AI Mode users (a provider figure).
- Citations: inline links, related-article links with thumbnails, news carousels and, in testing, an official sites section at the top of some responses. See Google AI Mode Explained.
- Price: free in Google Search; some features (for example information agents) start with Google AI Pro and Ultra subscribers.
- Ads in answers: labelled "Sponsored"; scaling in ten markets as of 28 October 2026, with Brazil, Mexico and the UK planned for Q4 2026, and multiturn ads in the US.
Kagi Search and Assistant
- Retrieval: Not stated by Kagi on the pricing page.
- Citations: Not stated by Kagi on the pricing page.
- Price: Trial (100 searches and 100 Assistant interactions), Starter $5 a month, Professional $10 a month, Ultimate $25 a month (Research mode and flagship models); 10% off annually. See Kagi Search and Kagi Assistant Explained.
- Ads in answers: Kagi states it has "no ads, no tracking".
Microsoft Copilot (consumer)
- Retrieval: Microsoft says Copilot "can search the web and provide concise summaries with sources"; Bing's grounding preferences cover web-grounded responses in Bing, Copilot and Microsoft 365.
- Citations: summaries with sources. See Microsoft Copilot Web Answers Explained.
- Price: a free baseline experience; Microsoft 365 Premium gives the highest usage limits. Prices are on the Microsoft 365 Premium page.
- Ads in answers: Not stated by Microsoft on the product page.
Perplexity
- Retrieval: PerplexityBot is "designed to surface and link websites in search results on Perplexity"; Perplexity-User fetches pages for a user's question.
- Citations: links to sources in answers. See Perplexity AI Explained.
- Price: Free, Pro, Education Pro ($10 a month with verification), Max, Enterprise Pro (from $40 a month or $400 a year per seat) and Enterprise Max; Comet Assistant queries are limited to 80 and 800 a month on Enterprise Pro and Enterprise Max. Pro and Max prices were not shown on the plans help page.
- Ads in answers: Not stated by Perplexity on the plans page.
Yahoo Scout
- Retrieval: Microsoft Bing's grounding API combined with Yahoo's own data and content.
- Citations: Yahoo describes "transparent sources"; format not detailed in the launch release.
- Price: Not stated by Yahoo in the launch release; available in beta to US users at Scout.Yahoo.com and in the Yahoo Search app.
- Ads in answers: Not stated by Yahoo in the launch release.
You.com
- Retrieval: Web Search, Contents, Answer, Research and Finance Research APIs, and an Inference Router with built-in web search.
- Citations: Not stated by You.com on the homepage.
- Price: custom enterprise pricing; list prices not shown on the homepage.
- Ads in answers: Not stated by You.com on the homepage.
How do publishers control AI use of their content?
Controls now separate three uses: appearing in AI search answers, being fetched when a user asks, and being used for model training. The table lists each provider's documented control by name.
| Provider | Search or answer inclusion | User-initiated fetches | Training or grounding preference |
|---|---|---|---|
| Googlebot via robots.txt; nosnippet, data-nosnippet, max-snippet, noindex limit what is shown | Not stated by Google on the AI features page | Google-Extended (training and grounding in some other Google systems) | |
| Microsoft | Bingbot; grounding preferences do not change search eligibility | Not stated by Microsoft in the preferences post | robots.txt token __usage_ai-training; Bingbot meta or X-Robots-Tag values ai-training and ai-grounding with Allow, DisallowExtended or Disallow |
| OpenAI | OAI-SearchBot (opting out keeps a site out of ChatGPT search answers) | ChatGPT-User (robots.txt rules may not apply) | GPTBot (disallow signals content should not be used for training) |
| Perplexity | PerplexityBot, controlled by robots.txt | Perplexity-User (generally ignores robots.txt) | Perplexity states PerplexityBot is not used to crawl content for AI foundation models |
As of 2026-11-15. Microsoft's dates: temporary grounding preferences open in Bing Webmaster Tools on 15 December 2026, the new preferences are honoured from 1 February 2027, NoArchive and NoCache stop being read as a training or grounding preference after 1 March 2027, and temporary preferences expire on 30 September 2027. Microsoft says DisallowExtended permits grounding only in Microsoft-operated experiences and excludes third-party grounding services.
What changed in 2026?
| Date | Event | Source |
|---|---|---|
| 16 January 2026 | OpenAI announces ads test for ChatGPT Free and Go in the US | OpenAI |
| 27 January 2026 | Yahoo launches Scout in beta for US users | Yahoo |
| 20 May 2026 | Google merges AI Overviews and AI Mode into one AI Search experience; Gemini 3.5 Flash becomes AI Mode default | |
| 15 October 2026 | Google adds more and higher inline links, tests an official sites section | |
| 28 October 2026 | Google scales AI Mode ads to ten more markets and launches multiturn ads in the US | |
| October 2026 | Microsoft announces ai-training and ai-grounding preferences for Bing | Microsoft |
As of 2026-11-15. The Ads in AI Answers Tracker follows ad rollouts by market.
How do I choose an AI answer engine?
Factual criteria only; weigh them against your own needs.
- Source transparency: check whether citations are inline, in a panel or both, and whether you can open each source in one click.
- Index origin: an engine with its own index and one built on a partner's grounding API can return different sources for the same question.
- Ads: confirm whether your plan and market show ads in answers and how they are labelled.
- Data handling: read what query and location data is sent to search partners or advertisers, and which settings turn personalisation off.
- Enterprise controls: for work use, confirm SSO, retention and training opt-outs per plan. See the Perplexity Enterprise Security and ChatGPT Enterprise Security Guide.
- Developer access: if you need grounding for your own agents, compare API pricing units (per request, per token) and rate limits.
Where identity and security fit
Answer engines create the same governance questions as any AI service. Staff may paste sensitive data into a free consumer engine, agentic browsers such as Perplexity Comet act on pages with the user's session, and search APIs are called with API keys that need rotation and scoping like any other machine credential. See the Safe Use of AI Chatbots Guide, the Agentic Browsers Security Guide and Blocking Personal ChatGPT, Claude and Gemini Accounts at Work.
Practitioner checklist
- Decide, per AI provider, whether you want to appear in AI search answers, and set OAI-SearchBot, PerplexityBot and Googlebot rules to match.
- Set training preferences separately (GPTBot, Google-Extended, Bing ai-training) so a training opt-out does not remove you from answers by accident.
- Diary Microsoft's dates: record temporary grounding preferences in Bing Webmaster Tools between 15 December 2026 and 1 March 2027 if you rely on NoArchive or NoCache.
- Check that key pages are indexed and snippet-eligible in Google Search, since that is the stated requirement for AI Overviews and AI Mode links.
- Track AI Mode and AI Overviews traffic in the Search Console Performance report under the Web search type.
- Write an acceptable-use rule for answer engines at work, naming approved plans with enterprise controls.
- Store and rotate search API keys (Brave, You.com and others) in a secrets manager with per-application keys.
- Recheck this page's facts against the official source before any decision; dates and markets change monthly.
Standards and references
- Google Search Central: AI features and your website
- Google: I/O 2026 announcements
- Google: Ads in AI Mode expansion
- OpenAI Help Center: ChatGPT search
- OpenAI: Overview of OpenAI crawlers
- Microsoft Bing Blogs: Clearer preferences for training and grounding
- Perplexity: Perplexity crawlers
- Brave: Brave Search API
Also checked on 2026-11-15: OpenAI: Our approach to advertising, Perplexity: subscription plans, Kagi: Pricing, Microsoft: Copilot for individuals, Yahoo: Introducing Yahoo Scout, You.com, Google: More ways to connect with the web from Search.
Related NHI Mgmt Group resources: Google AI Mode Explained · ChatGPT Search vs Perplexity · What Is Answer Engine Optimisation (AEO)? Definition, Signals and Measurement · Brave Search and Ask Brave Explained · Safe Use of AI Chatbots Guide