AEO vs GEO vs SEO: how to get found in AI search in 2027

SEO is the work of making pages findable and useful in search engines. AEO (answer engine optimization) and GEO (generative engine optimization) are newer labels for earning visibility inside AI answers. Google's own guide, published on 15 May 2026, says that for Google Search, optimizing for generative AI search is still SEO. Evidence for tactics aimed at other assistants is much thinner.

What is the difference between AEO, GEO and SEO?

AEO, GEO and SEO describe overlapping work. The table shows what each term aims at and who stands behind the definition.

Google lists AEO and GEO side by side and does not separate them, so the practical difference is mostly the label. A page that is crawlable, indexed, clear and original serves all three goals. The CMO Survey's 2026 edition, fielded in January 2026 among 308 US marketing leaders, found 41.5% of companies already using GEO. An earlier explainer on why answer engine optimization matters covers the background.

What does Google document about AI Overviews and AI Mode?

Google documents that AI Overviews and AI Mode are built on the same Search index and ranking systems, and that no special optimization is needed to appear in them. Two techniques sit underneath, according to Google's guide. Retrieval-augmented generation pulls relevant pages from the Search index, and query fan-out has the model issue several related searches at once. For the query "how to fix a lawn that's full of weeds", Google's example fan-out searches include "best herbicides for lawns" and "how to prevent weeds in lawn".

A page must be indexed and eligible to appear in Google Search with a snippet, which means Googlebot is not blocked, the page returns an HTTP 200 status and it has indexable content. Meeting those conditions does not promise that a page is shown. Google's 2026 guide adds one more condition: the site must be included through the Search generative AI control in Search Console. Inclusion is the default, so a site is in unless its owner opts out.

AI Overviews do not appear on every search. Google says they show only when its systems judge them additive, and Pew Research Center found an AI summary on 18% of the Google searches it sampled from US adults in March 2025. Longer and question-style searches triggered them more often: 60% of searches that began with a question word did, against 8% of one- or two-word searches.

For readers in India, Google said on 8 October 2025 that AI Mode was live in English and Hindi, with Bengali, Kannada, Malayalam, Marathi, Tamil, Telugu and Urdu rolling out.

How do ChatGPT, Claude and Perplexity find pages?

Each assistant publishes crawler names that decide whether its search feature can fetch a page, but the vendors do not document how sources are chosen. The table lists the access controls the vendors document.

Blocking a training bot does not block a search bot, because each setting is independent. A robots.txt file that blocks training and keeps search open looks like this:

User-agent: GPTBot
Disallow: /

User-agent: ClaudeBot
Disallow: /

User-agent: OAI-SearchBot
Allow: /

User-agent: Claude-SearchBot
Allow: /

User-agent: *
Disallow: /admin/

Running that file through Python's urllib.robotparser gives a surprising result. OAI-SearchBot and Claude-SearchBot are allowed to fetch /admin/, because a crawler that has its own group does not read the group. RFC 9309, the Robots Exclusion Protocol, states the rule: a crawler obeys the group that names it and falls back to only when no group names it. Googlebot and PerplexityBot have no group of their own, so they are kept out of /admin/, and GPTBot and ClaudeBot are blocked everywhere.

User-triggered fetchers behave differently. OpenAI says ChatGPT-User may not follow robots.txt rules because a person started the visit, and Perplexity says Perplexity-User generally ignores them. A robots.txt file is a crawl signal, not a lock.

Which AI search tactics are documented, and which are unproven?

Only the first three tactics in the table below are documented by the company that runs the search feature. The rest are suggestions, tests or claims that no vendor page confirms.

Anything outside the first three rows is a hypothesis to test on a small set of pages, not a rule to roll out across a site.

Does structured data help with AI search?

Google says structured data is not required for AI Overviews or AI Mode, and that there is no special schema.org markup for them. It still recommends keeping structured data as part of an overall SEO plan, because it supports rich results. The one firm rule is that markup must describe content visitors can see on the page. Google says JSON-LD is, in most cases, the easiest format to maintain.

Markup chosen for looks can disappear. Google stopped showing FAQ rich results from 7 May 2026 and removed the documentation on 15 June 2026. No vendor documentation shows structured data raising citations in ChatGPT, Claude or Perplexity, so the sensible position is valid markup for rich results and no promise of more.

What is a practical checklist for getting found in AI search?

A checklist built only from vendor guidance covers most of the work, and each line below comes from Google's or Microsoft's own published advice.

• Let Googlebot and the search bots of the assistants you want (OAI-SearchBot, Claude-SearchBot, PerplexityBot) fetch the site, and check CDN and hosting rules as well as robots.txt.
• Publish what only your organisation can: first-hand data, worked examples, original research and real experience, which Google calls non-commodity content.
• Organise pages into paragraphs and sections with clear headings, which Google says readers appreciate and Microsoft says helps AI systems reference a page.
• Keep text, images and video consistent about the same entities and products, as Microsoft advises, and keep Merchant Center and Business Profile details current, as Google advises.
• Keep structured data valid and identical to the visible text.
• Support text with high-quality images and video where they help the reader.
• Refresh facts when they change, and use IndexNow if Bing visibility matters.

A step-by-step plan for the content itself is in the guide to content marketing strategy.

How do you measure visibility in AI search?

Two first-party reports now count AI search visibility. Google Search Console has a generative AI performance report that counts impressions in AI Overviews and AI Mode by page, country, device and date, and Google says it rolled out to all websites worldwide as of 31 August 2026. Bing Webmaster Tools has an AI Performance report, in preview since February 2026, that counts citations in Copilot and Bing AI summaries and lists the grounding queries behind them.

Microsoft added Citation Share in June 2026, defined as a site's share of citations for one grounding query. The two reports count different things, impressions in one case and citations in the other, so they cannot be added together.

Google Analytics 4 adds a view of visits. Visits from assistants such as ChatGPT, Gemini, Copilot and Grok fall into an AI Assistant channel, while clicks from AI Overviews and AI Mode are counted as Organic Search.

SEO tool vendors also sell AI visibility scores. Google notes that no third-party tool has access to its internal ranking or AI systems, so those scores are the vendor's estimate, not a Google measurement.

Google says clicks from pages with AI Overviews are higher quality, but publishes no data on that page. Pew Research Center found that US users clicked a result link in 8% of visits with an AI summary and 15% without one in March 2025, and clicked a link inside the summary in 1% of visits. Neither statement measures India.

What are the limits of AEO and GEO advice?

Much AEO and GEO advice comes from third parties, and Google tells site owners to verify such advice against its official guidance. Google adds that good advice either labels itself as opinion based on data or experience or cites official guidance.

The evidence is also thin and dated. The 2023 GEO paper, accepted to KDD 2024, used a test engine built on GPT-3.5 turbo and one live engine, and its authors note that methods may need to adapt as generative engines change and that they did not test effects on rankings. A citation count is not traffic either, and Microsoft says its citation metrics do not indicate ranking, authority or placement.

There is a trade-off in access, too. Blocking a search bot can remove a site from that assistant's answers, while blocking a training bot does not. A publisher has to decide which of the two it wants, and the choice is separate for each vendor.

Where does AI search fit in digital marketing training?

AI search is one more surface for the same fundamentals: clear pages, original content and measurement. The Certification Program in Digital Marketing with Applied AI, IIM Ranchi is an online programme from IIM Ranchi, run with Masai as the implementation partner, taught in live online classes with an optional campus immersion at IIM Ranchi, covering SEO, social media, email, paid ads, analytics and generative AI tools such as ChatGPT, with a capstone project.

Its modules include Creating Content and Getting Found on Google and Measuring Success and Automating Emails. Readers new to the basics can start with an explainer on what SEO is in digital marketing.

Frequently asked questions

What is the difference between AEO and SEO?

SEO is about helping search engines understand content and helping users find a site, while AEO is a label for work on visibility in AI search experiences. Google's guide of 15 May 2026 says that, from Google Search's perspective, optimizing for generative AI search is still SEO. The difference is mostly one of label and target, not of method.

What is GEO in marketing?

GEO stands for generative engine optimization, work aimed at improving the visibility of content in generative engine responses. A 2023 research paper formalised the term. The CMO Survey's 2026 edition found 41.5% of US companies surveyed already use GEO. Google treats it as part of SEO for its own features.

Does structured data help with AI search?

Google says structured data is not required for AI Overviews or AI Mode and that no special schema exists for them. It remains useful for rich results, and it must match the text visible on the page. No vendor documentation shows structured data increasing citations in ChatGPT, Claude or Perplexity.

Does a site need an llms.txt file?

Google says Google Search ignores llms.txt files, so the file neither helps nor harms visibility in Google Search. Creating one for other services that use it is optional. No vendor page for ChatGPT, Claude or Perplexity names llms.txt as a signal, so any benefit there is unproven.

How can a site check whether AI search sends it traffic?

Google Search Console's generative AI performance report shows impressions from AI Overviews and AI Mode, and AI Mode and AI Overviews traffic also sits inside the normal Performance report under Web. Bing Webmaster Tools shows citations. Google Analytics 4 groups visits from assistants such as ChatGPT in an AI Assistant channel.

Should a site block AI crawlers?

The choice depends on the goal. Blocking training bots such as GPTBot and ClaudeBot does not remove a site from ChatGPT or Claude search, while blocking OAI-SearchBot or Claude-SearchBot can. Google-Extended affects Gemini training and grounding but not Google Search inclusion. Each setting is independent, and a robots.txt file is not a lock.

Next step

The Certification Program in Digital Marketing with Applied AI, IIM Ranchi covers SEO, content, analytics and generative AI tools in live online classes. Before choosing any course or tool, check each claim about AI search against the vendor's own documentation, and compare reporting options in the list of top SEO tools for 2027.