AI Search Engine Optimization: What It Is and How to Start

TL;DR

What it is: getting AI engines to name your brand and cite your pages.
Where a page fails: three places. Not in the index. No match for the engine's queries. Or another page is easier to quote.
Engines differ: for "best SEO tool", only 2 of 14 products are named by all five. And one robots.txt rule can remove you from ChatGPT search.
Mostly SEO: Google says it's still SEO. Four things are new.
First week: eight steps. Write prompts, run them, check bots and indexing, fix one page, run them again.

Does AI name your brand? Check your site.

Someone asks ChatGPT a question.

It answers with a few brands and a few links.

AI search engine optimization is the work of being one of them.

The engines: ChatGPT, Perplexity, Gemini, Copilot, and Google's AI Overviews and AI Mode.

(Some people use the phrase for something else: using AI tools to do SEO. That's ChatGPT for SEO.)

Here's the part most guides skip. Google says optimizing for its AI search is still SEO.

So most of the work is the SEO you already do.

Mostly SEO, four things are new: more crawlers, prompts are full questions, other sites show up in the answer, and no fixed rank to track — The four new parts. The rest is SEO.

Below: how an engine picks a page, where a page fails, one real question on five engines, and a first-week checklist.

What AI search engine optimization means

Someone asks an AI engine a question. They get one written answer.

It names a few brands. It links a few sources.

You want to be one of those brands and sources.

Count both. They are not the same.

Two outcomes count:

A mention: the answer names your brand in its text.
A citation: the answer links one of your pages as a source.

You can get one without the other.

An answer can name you and cite a review site. Or cite your comparison page and recommend a competitor.

What about all the other names?

AEO (answer engine optimization). GEO (generative engine optimization). LLM SEO. AI SEO.

They describe the same job. I compare them in AI SEO vs LLM SEO vs GEO vs LEO.

Google's guide to generative AI features (updated July 2026) defines AEO and GEO. Then it says that for Google Search the work is "still SEO".

Pick one name. Move on.

How AI Models Choose Which Content to Cite

No engine publishes its full selection logic.

But the documented parts point to the same four steps.

Four steps from prompt to answer: decide to search, write its own queries, retrieve from an index, write the answer and attach sources. Three places a page can fail: not in the index, no match for the queries, another page is easier to quote — Fail 1 and fail 2 happen before the engine writes anything. Check those first.

1. The engine decides whether to search.

OpenAI's web search guide for developers says the model can search the web or not, based on the prompt. (That guide covers the API, not the ChatGPT app.)

No search? The answer comes from training. No retrieved pages to cite.

2. It writes its own search queries.

They can differ from the user's words.

Google calls this query fan-out: several related searches across subtopics.
OpenAI's help page for ChatGPT search says that when ChatGPT search uses other search providers, it typically rewrites your query into one or more targeted queries.
Microsoft says Microsoft Copilot sends Bing a query of a few words that it derives from the prompt.

3. It retrieves pages from a search index.

It does not read the whole web.

A page that is not in that index does not come up. What an LLM search engine is goes deeper.

4. It writes the answer and attaches sources.

It quotes or paraphrases a few retrieved pages. And links them.

Where a page fails and what to check

That gives three places to fail.

The first two happen before the engine writes the answer.

Writing advice helps with the third only. So check the first two before you rewrite anything.

What you see	Where it breaks	What to check
Never named, never cited, even for your own brand	The page is not in the index the engine uses, or a bot is blocked	Search Console, Bing Webmaster Tools, robots.txt, firewall and CDN rules
Competitors named, you are not, and your page is indexed	The page does not match the queries the engine wrote	Run the prompt, read the pages it cites, and put the answer and the specifics in text
Named but not linked, or a rival is recommended in the same answer	Another page was easier to quote	List the cited pages (on buyer questions, often roundups). Fix your page or get onto those lists

How it differs by engine

Each engine reads a different index. So each needs a different check.

Engine	What it reads	Your check
Google AI Overviews and AI Mode	Google's index. A page must be indexed and eligible for a snippet, with no other technical requirements. The site must also be included in Search generative AI features in Search Console.	Indexing in Search Console, and that setting
Gemini	Google Search results, through grounding. The linked page covers the Gemini API.	Indexing in Google, and your `Google-Extended` rule
ChatGPT	`OAI-SearchBot` crawls for ChatGPT search. A site that opts out does not show in ChatGPT search answers, though it can still appear as a navigational link.	robots.txt and firewall allow `OAI-SearchBot`
Perplexity	`PerplexityBot` finds and links sites for Perplexity's results. Perplexity recommends that you allow it.	robots.txt and firewall allow `PerplexityBot`
Copilot	Bing, documented by Microsoft for Microsoft Copilot and Copilot Chat.	Indexing in Bing Webmaster Tools

Two pairs of names cause mistakes.

Two pairs people mix up: GPTBot is for training data and is not OAI-SearchBot, which is for ChatGPT search. Google-Extended is for Gemini training and grounding and is not Googlebot, which is for Google Search — Block the wrong one and you vanish from the wrong place.

GPTBot is not OAI-SearchBot. OpenAI uses GPTBot for training data and OAI-SearchBot for search. You can block the first and allow the second.
Google-Extended is not Googlebot. It controls whether Google can use your content to train Gemini models and to ground Gemini answers. Google says it has no effect on inclusion or ranking in Google Search.

The crawler rules to check

Allow the two search bots.

Blocking GPTBot is a choice. Not a recommendation.

User-agent: OAI-SearchBot
Allow: /

User-agent: PerplexityBot
Allow: /

# Optional: opt out of OpenAI training use, which does not affect ChatGPT search
User-agent: GPTBot
Disallow: /

Three things an Allow line doesn't cover:

User-triggered fetchers. OpenAI says ChatGPT-User starts from a user action, so robots.txt rules may not apply. Perplexity says Perplexity-User generally ignores robots.txt.
Firewalls. An Allow line does nothing if your firewall or CDN blocks the bot. OpenAI and Perplexity publish IP ranges to allow. Google lists crawling allowed by any CDN or hosting infrastructure as a basic.
Delay. OpenAI says a robots.txt change can take about 24 hours to reach search. Perplexity says up to 24 hours.

A Google ranking helps more on some engines than on others

How many cited URLs also sit in Google's top 10 for the same query?

Ahrefs measured it.

Bar chart of cited pages that also rank in Google top 10: 38% for AI Overviews in a March 2026 study, 28.6% for Perplexity and about 8% for ChatGPT, Gemini and Copilot in a 2025 study — Two Ahrefs studies. Different dates, different methods.

Google AI Overviews: 37.9% (first 10 blocks of the results page). From 863,000 keyword results pages, published March 2026.
Perplexity: 28.6%. From 15,000 prompts collected in early July 2025.
ChatGPT, Gemini, and Copilot: 6% to 9% each. Same 2025 study.

The studies differ in date and method. So do not compare the numbers closely.

But the point holds. A top-10 ranking does not guarantee a place in the answer.

And most cited URLs do not rank in the top 10.

The same question on five engines

Our leaderboard scans each question on all five engines every month.

Here is best SEO tool. Scanned on 24 September 2026. 14 products.

Leaderboard table of 14 SEO tools with a rank per AI engine — AI SEO Tracker leaderboard for best SEO tool. Columns left to right: ChatGPT, Perplexity, Gemini, Google AI Overviews, Copilot. Scan of 24 September 2026; screenshot taken 2 October 2026.

Best SEO tool, 14 products, 5 engines: 2 products are named by all five engines and 7 are named by one engine only. AI SEO Tracker leaderboard, scan of 24 September 2026 — Two everywhere. Seven in one place only.

Ahrefs and Semrush are named by all five engines.
Ahrefs: first on ChatGPT. Sixth on Gemini.
Semrush: first on Perplexity, AI Overviews and Copilot. Fifth on Gemini.
Google Search Console is named by four engines. Not Perplexity.
Yoast SEO is named by two. First on Gemini. Eighth on Copilot.
Seven of the 14 products are named by one engine only.

One question on one date is not a sample of the market.

It does show this: one engine's answer tells you little about another's.

What carries over from SEO and what is new

What carries over.

SEO is still worth doing.

Google says its generative AI features are rooted in its core Search ranking and quality systems.

Its AI features documentation lists the same basics as for Search:

Let crawlers in
Link pages internally
Keep key content in text
Make structured data match the page

Its guide puts one thing above the rest: non-commodity content. A first-hand review, not a summary of what already exists.

What is new. Four things.

1. More crawlers.

Googlebot is no longer the only one that matters. See the table above.

2. Full questions.

A prompt can be a full question with the buyer's situation in it.

So write pages that answer one specific question: "best X for Y", a comparison, an alternatives page. (LLM SEO covers this.)

Do not make a page for every variation. Google's guide says doing that mainly to manipulate rankings or AI responses breaks its scaled content abuse policy.

3. Other sites show up in the answer.

Google's guide says its AI features can show what blogs, videos, and forums say about products.

In the leaderboard scan above, 24 pages were cited:

21 by one engine only
3 by two engines
0 by three or more

Table of the first ten pages cited for best SEO tool, with the engines that cited each — The first ten cited pages from the same scan. The Cited by icons are the engines; 21 of the 24 cited pages were cited by one engine only. Screenshot taken 2 October 2026.

Across the leaderboard's 343 "best X" questions, 77% of cited pages are listicles. 10% are vendor pages.

That is buying questions only. See how to get on the lists AI engines cite.

4. Measurement.

There is no fixed rank to track. You count mentions and citations for each prompt.

And what does the research say about writing?

The GEO paper from Princeton and IIT Delhi (KDD 2024) compared nine ways to rewrite a page.

Cited sources, quotations, statistics: visibility up 30 to 40% on its word-count measure.
Keyword stuffing: little to no improvement.

It ran on a simulated engine built on GPT-3.5. So read it as a direction.

$49 report

Does AI name you?

See if AI mentions your brand. Then get the pages to fix.

Check one question free How it works

What you can skip

For Google Search, Google's guide says you do not need:

llms.txt files (Search ignores them)
Content chunking
A special writing style for AI
Special schema

That is Google speaking about Google Search. Not about ChatGPT or Perplexity.

I would still not spend the first week on any of the four.

If a page is not crawled, not indexed, or not worth quoting, a text file does not change that.

A first-week checklist

Your first week in eight steps: write 10 to 20 prompts, run each one by hand, check robots.txt and firewall, check indexing in Google and Bing, view pages without JavaScript, fix one page, list the cited third-party pages, run the same prompts again — Eight steps. Steps 2 and 8 are the slow ones.

1. Write 10 to 20 prompts.

Use full buyer questions:

"best [category] for [use case]"
"alternatives to [competitor]"
"is [your brand] worth it"

The free keyword research tool finds prompts from buyer questions.

2. Run each prompt by hand.

Use ChatGPT, Perplexity, Gemini, Copilot, and Google. Not sure where to start? Test one prompt in ChatGPT with the free AI Visibility Checker.

Try two or three wordings of each. Engines rewrite prompts into their own queries.

Log six things in a sheet: the prompt, engine, date, whether you were named, the cited URLs, and the competitors named.

Tip: Microsoft says Copilot's citation section shows the exact queries sent to Bing. (Documented for Microsoft Copilot and Copilot Chat.)

3. Read your robots.txt and your firewall rules.

Make sure neither blocks OAI-SearchBot, PerplexityBot, Googlebot, or Bingbot.

Copilot reads Bing. AI Overviews read Google's index.

Decide on GPTBot and Google-Extended separately.

4. Check indexing in two places.

Google Search Console and Bing Webmaster Tools.

In Search Console, confirm that the site is included in Search generative AI features.

5. Look at your key pages without JavaScript.

Vercel's December 2024 crawler study found that the crawlers of OpenAI, Anthropic, and Perplexity did not render JavaScript. Gemini, through Google's infrastructure, and Applebot did.

Check yours. View the source. Search for your price or product name.

The free Page Inspector shows what AI can read on a page.

6. Fix one page.

Take the page that should answer your most important prompt.

Put the answer in the first paragraph.
State the specifics in text: what the product is, who it is for, what it costs.
Link your sources.

7. List the third-party pages the engines cited.

They are in your sheet from step 2. Review sites, roundups, forum threads.

They cite a roundup that does not list you? Getting onto that roundup is the task.

8. Set a date to run the same prompts again.

Same wordings. Same engines. Same sheet.

Why again? Because answers move.

Ahrefs studied more than 43,000 keywords, each with at least 16 recorded AI Overviews in a month:

70% chance an AI Overview changed between one observation and the next.
45.5% of its cited URLs were new, on average.

That is AI Overviews only. I have no such figure for ChatGPT or Perplexity.

Treat one check as one reading.

Steps 2 and 8 are the slow ones.

The AI SEO Tracker report does them for you. $49 once. Up to 50 prompts written from your site. Scanned daily for 7 days on ChatGPT, Perplexity, Gemini, Copilot, and Google AI Overviews.

A sheet is enough if you have ten prompts.

How to know if it is working

Count two things for each engine:

Mention rate: how many of your prompts name you.
Citation rate: how many cite one of your pages.

Compare the numbers with the last run.

Two first-party reports help.

Google Search Console has a Generative AI performance report.

It counts impressions: how many times a link to your site was shown in AI Overviews and AI Mode. Google says it reached all websites worldwide as of 31 August 2026.

Google also reports traffic from AI features in the Performance report, under the Web search type.

Bing Webmaster Tools has an AI Performance report. In public preview since February 2026.

It shows how often your pages are cited in Copilot, in Bing's AI summaries, and in some partner integrations that Bing does not name. Plus a sample of the grounding queries.

The counts do not show ranking or placement in an answer.

Server logs add a third signal.

OpenAI and Perplexity publish their bots' user-agent names and IP ranges. So you can count visits.

But a visit shows a bot fetched a page. Not that an answer cited it.

One limit on every tracker. Ours too.

Google says no third-party tool has access to its internal ranking or AI systems. So any tracker measures what an engine answers. Not why.

The AI SEO Tracker report scans five engines: ChatGPT, Perplexity, Gemini, Copilot, and Google AI Overviews.

It does not scan Google AI Mode, Claude, Grok, DeepSeek, or Meta AI.

How fast will you see a change?

I have no sourced number. So I will not give you a number of weeks.

Run the same prompts on a fixed schedule. Read the trend.

Where to go next

Tactics: AI search optimization
After week one: AI SEO strategy
Earning citations: how to get cited in AI answers
One engine at a time: ChatGPT, Perplexity, Google AI Overviews
Measuring it: how to measure brand visibility in AI