AI search, explained

LLM SEO: getting mentioned by ChatGPT, Claude, Gemini, and Perplexity

Large language models now answer a lot of the questions people used to type into Google. LLM SEO is how you make sure your business is one they know about and trust enough to name.

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Quick answer: LLM SEO is the work of getting your business mentioned and cited by large language models like ChatGPT, Claude, Gemini, and Perplexity. Those tools answer from what they learned in training plus what they find searching the web live, so LLM SEO means being indexed, writing pages with clear, quotable answers, keeping your business facts consistent everywhere, and earning genuine mentions. Tools can track whether you show up, but nobody can guarantee a mention.

LLM SEO is one of several names for the same shift. If you're sorting out the acronyms, start with our SEO vs AEO vs GEO overview.

What is LLM SEO?

An LLM, or large language model, is the technology behind ChatGPT, Claude, Gemini, and the answer engine in Perplexity. When a customer asks one of them "who's a good bookkeeper for restaurants in Denver?", it writes a short answer and often names a few businesses. LLM SEO is everything you do to be one of those names, and to be described accurately when you are.

It's the same idea as generative engine optimization (GEO), just named after the model instead of the engine. People searching "SEO for LLM" usually want the practical version: what these models read, what makes them pick one source over another, and what you can actually change.

How do LLMs pick which sources to use?

There are two very different ways a business ends up in an LLM's answer, and they call for different expectations.

  • Training data. Each model learned from a huge body of text collected up to a cutoff date. If your business was widely written about before then, the model may "know" you without searching. For most small businesses, that knowledge is thin or missing, and you can't update it on demand. It changes only when a new model is trained.
  • Live retrieval. For current, local, or specific questions, most assistants now search the web, read a handful of results, and build the answer from them. This is the part you can influence. If your page is indexed, clear, and backed up by other sources, it has a real chance of being read and cited.

In practice, retrieval-based answers tend to favor sources that make the answer easy and safe to repeat: a direct answer near the top of the page, specific facts (services, areas, hours, price ranges), and a business identity that matches across your site, your Google Business Profile, directories, and reviews. Nobody outside these companies can see exactly how they rank sources, and it changes, but that pattern holds up well.

How do you do LLM SEO?

Most of it is ordinary good practice, pointed at a new kind of reader.

  • Be indexed. Submit a sitemap in Google Search Console and Bing Webmaster Tools. AI tools that search the web lean on search indexes, so a page no search engine has seen is hard for them to find.
  • Don't block the crawlers you want. Check robots.txt for rules that block AI search crawlers or all bots. Some security plugins add these quietly.
  • Lead with the answer. Open each key page with a one or two sentence answer, then use customer questions as headings with short answers underneath.
  • Be specific. Name your services, areas, and who you serve. "We do payroll and monthly books for restaurants in Denver" is quotable; "tailored financial solutions" isn't.
  • Add structured data. LocalBusiness and FAQ schema label your facts for machines.
  • Make your facts match everywhere. Same name, address, phone, hours, and services on your site, Google Business Profile, and directories.
  • Earn mentions and reviews. Other reputable sites naming you, and recent genuine reviews, give a model evidence you're real and well regarded.

For platform-specific steps, see how to rank in ChatGPT and how to rank in AI Overviews.

What do LLM SEO tools actually do?

The market for LLM SEO tools and LLM visibility tools is young and crowded, and names change fast. Rather than pick winners, here are the categories and what each one is good for.

  • Visibility and mention tracking. You give it a list of prompts ("best dog groomer in north Austin"), and it runs them through several AI assistants on a schedule, logging whether you're named, where in the answer, and who's named instead. Output is usually a share-of-voice style score.
  • Prompt and citation monitoring. Watches specific questions over time and records which web pages the assistants cite. This is often the most useful data: it tells you which directories, articles, and competitor pages AI trusts for your topic.
  • Content and structure checkers. Review your pages for things that make them easier to quote: answer-first openings, question headings, FAQ sections, structured data, and crawler access.

One caution applies to all of them. AI answers vary by wording, location, account, and plain chance, so a tool's score is a sample of the prompts it ran, not a fixed rank. Use it to watch the trend over months, not to celebrate or panic over one week.

Should you do LLM SEO yourself, use a tool, or hire a service?

The honest trade-offs. Costs are described loosely because they vary so much; get real quotes.

Do it yourselfLLM SEO toolLLM SEO service or agency
What you getYou run the checks and make the changesAutomated prompt tracking, dashboards, alertsSomeone else plans the work and makes the changes
CostYour time, a few hours a monthA monthly subscription; varies widely by prompts trackedA monthly retainer or project fee; varies widely
Fixes anything?Yes, if you do the workNo, it measures; you still make the changesYes, if the scope includes content and listings
Best forOne location, a handful of key questionsMany questions, locations, or competitors to watchOwners with no time and a budget to delegate
Watch out forLetting the monthly check slideReading a sample score as a hard rankingGuaranteed placements and vague reporting

A tool measures; it doesn't fix. Whatever you choose, someone still has to improve the pages and listings.

What is llms.txt, and does it help SEO?

llms.txt is a proposed convention: a plain text (Markdown) file you put at yoursite.com/llms.txt that briefly describes your site and lists links to your most useful pages, in a format that's easy for a language model to read. The idea is a bit like a sitemap written for AI instead of for search crawlers.

Here's the honest status:

  • It's not a standard. It's a community proposal, not something adopted by a standards body or required by any search engine.
  • There's no public evidence the major engines rely on it. The big AI assistants haven't said they use llms.txt to choose sources, and it isn't a Google ranking signal.
  • It's cheap to add. A short file with your business description and links to your key service pages takes minutes and does no harm.

So add one if you like, but don't expect it to move anything on its own, and be skeptical of anyone selling llms.txt as the key to AI visibility. Clear pages, structured data, and consistent facts are what the evidence actually supports.

What does LLM SEO look like for one small business?

An illustrative example (not a real customer): a two-person bookkeeping firm in Denver that serves restaurants. The owner writes down eight questions clients actually ask, like "restaurant bookkeeper in Denver" and "who does payroll for small restaurants in Colorado", and asks each one in ChatGPT, Gemini, and Perplexity, in a fresh chat. That's 24 answers. Say the firm is named in 2 of them, and a local business directory and a competitor's blog are cited again and again.

Over the next two months, the owner rewrites the restaurant page to open with a plain answer ("We handle monthly books, payroll, and sales tax filings for independent restaurants in Denver"), adds a six-question FAQ with schema, fixes an old phone number on two directories, and asks a few happy clients for reviews. Then the same 24 checks again. In this example, the firm shows up in 6.

Those numbers are made up to show the method, not a promise. Real results depend on your market and how the assistants change. The method is the point: fixed questions, a monthly check, and changes aimed at whatever the assistants are citing.

How Lightsky helps with LLM SEO

Lightsky's SEO assistant audits your site, drafts and optimizes pages, and reads Search Console. As an optional add-on, it handles the LLM side too: it drafts your pages around the exact questions customers ask with the answer stated plainly up top, adds FAQ and business structured data, helps keep your name, address, phone, and services consistent with your Google Business Profile, and finds places that mention your business without linking to it, then drafts friendly outreach for you to send.

You approve everything before it publishes. It's free to start, then pay as you go with credits, with no per-seat fees. And to be straight about it: Lightsky can't guarantee that ChatGPT, Claude, or Gemini will mention you. Nobody can. See AI SEO for how the assistant works.

The bottom line

LLM SEO is about being findable, quotable, and trustworthy to the AI tools your customers ask. You can't change what a model learned in training, but you can shape what it finds when it searches: clear pages, structured data, consistent facts, and real mentions. Track it with a simple monthly check or a tool, and treat llms.txt as a nice extra, not a fix.

Frequently asked questions

What is LLM SEO?

LLM SEO is the practice of making your business easy for large language models, like ChatGPT, Claude, Gemini, and Perplexity, to find, understand, and mention when they answer a question. It's closely related to generative engine optimization (GEO); the names are mostly interchangeable.

How is LLM SEO different from regular SEO?

Regular SEO aims to rank a page in a list of search results. LLM SEO aims to get your business named inside the answer an AI writes. The two overlap a lot, because LLMs that search the web lean on search indexes, but LLM SEO puts more weight on quotable answers, consistent business facts, and mentions on other sites.

How do LLMs decide which sources to use?

Two ways. First, what the model learned during training, which is fixed at a cutoff date and thin on small local businesses. Second, what it finds when it searches the web in the moment, which most assistants now do for current and local questions. For a small business, the live search side is usually where you can make a difference.

What do LLM SEO tools do?

Most fall into three groups: visibility or mention trackers that run a set of prompts through several AI tools and log whether you're named; prompt monitoring that watches specific questions over time and shows which sources get cited; and content or structure checkers that review your pages for clear answers, headings, and structured data.

Do I need an LLM SEO tool?

Not to start. You can check your own visibility by asking ChatGPT, Perplexity, and Gemini your customers' real questions once a month and logging the answers in a spreadsheet. A tool mainly saves time when you track many questions, many locations, or several competitors.

Are LLM visibility scores accurate?

Treat them as samples, not rankings. AI answers vary from one run to the next and by wording, location, and account, so a tool's score reflects the prompts it happened to run. Useful for spotting trends over months; not a precise position like a Google rank.

What is llms.txt?

llms.txt is a proposed convention: a plain text file at the root of your site (yoursite.com/llms.txt) that summarizes your site and points to your most useful pages in a format language models can read easily. It is not an official web standard, and there's no public evidence the major AI search tools rely on it yet.

Does llms.txt help SEO?

Not in any proven way today. Search engines don't treat it as a ranking signal, and the major AI assistants haven't said they use it to choose sources. It's cheap to add and harmless, so some businesses add one, but it won't replace clear pages, structured data, and consistent facts.

Should I hire an LLM SEO agency or service?

It can make sense if you don't have time to do the work yourself. Ask what they'll actually change on your site and listings, how they'll report results, and how they handle the fact that AI answers vary. Walk away from anyone who guarantees a ChatGPT or Gemini placement; nobody can.

Should I block AI crawlers?

That's a business choice, but if you want to show up in AI answers, don't block the crawlers AI assistants use to search the web. Some companies run separate crawlers for search and for model training, which you can often control separately in robots.txt. Check each company's current crawler documentation before you change anything.

How long does LLM SEO take to work?

Weeks to months, with no set timeline. A new or updated page has to be crawled and indexed before an AI can find it in search, and training data only refreshes when a new model is built. Check monthly and look for the trend.

How does Lightsky help with LLM SEO?

As an optional add-on, Lightsky's SEO assistant drafts pages around the questions customers ask with the answer stated plainly up top, adds FAQ and business structured data, helps keep your name, address, phone, and services consistent with your Google Business Profile, and finds unlinked mentions so you can reach out. You approve everything, and it can't guarantee an AI mention.

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