What Is LLM Optimization (LLMO)?
LLM optimization (LLMO) is the work of shaping what large language models such as ChatGPT, Claude and Gemini know and say about your business. It covers two routes: the web pages an assistant looks up live, and the older text a model absorbed during training. Most of what you can control sits in the first route.
- LLMO is mostly a new name for AI SEO. Its one useful idea is the split between training memory and live lookup.
- You can influence live lookup directly. You cannot see or edit training data, only shape the public web it learns from.
- Letting search bots in while deciding separately about training bots is the main crawler setting to get right.
- Evidence for brand-mention effects is correlation only, and no engine has confirmed that llms.txt files help.
What is LLM optimization?
LLM optimization is the practice of making your business easy for large language models to find, understand and describe correctly. A large language model (LLM) is the AI system behind tools like ChatGPT, Claude and Gemini. It writes answers by predicting text, using what it learned in training and, often, pages it fetches at the moment you ask.
The term LLMO appeared because people wanted a label for 'being well represented inside these models'. Nobody owns the definition, and different vendors use it slightly differently. We use it in the broad sense: every action that changes how an LLM-powered assistant talks about you.
In practice that means three jobs. Let the right bots read your site. Publish pages that answer buyer questions clearly. Earn mentions of your name on sites the models trust.
How is LLMO different from AEO, GEO and AI SEO?
For a business owner, the difference is small. The four labels describe overlapping work, and the same page edits serve all of them. The table shows where each label puts its emphasis.
If a vendor sells LLMO as a separate service, ask what they would do differently from a good AI SEO plan. A clear answer should mention training data, crawler settings or brand mentions. A vague answer means the label is doing the selling.
| Label | Emphasis | Typical goal |
|---|---|---|
| AI SEO | The whole programme: search plus AI answers | Be found and cited across Google and AI assistants |
| AEO | Answer engines and featured answers | Be the single quoted answer to a question |
| GEO | Generated answers that cite sources | Be cited inside an AI-written response |
| LLMO | The model itself, memory and lookup | Be known and described correctly by the model |
How does an AI model learn about your business?
A model learns about you in two ways: from its training memory, and from live lookup. The 2020 research paper that defined retrieval-augmented generation (RAG) describes the same split. It combines a model's stored 'parametric' memory with an outside index it can search 1.
Live lookup is the part you can steer. Anthropic's developer documentation for Claude's web search tool says Claude searches when a request depends on information that is current, changing or outside its training data, including information about specific organisations, people or products that might have changed 2. Other assistants decide differently. Pricing, reviews, new services and 'best provider' questions all fall into that group.
Training memory is slower and mostly out of your hands. The model absorbed text from a past crawl, and it usually cannot show where a given belief came from. We found no reliable public study that measures how much one brand's pages shift a model's trained knowledge, so treat anyone who claims to engineer it with caution.
| Question | Training memory | Live lookup |
|---|---|---|
| What is it? | Patterns learned from text before a cutoff date | Pages fetched when the question is asked |
| How fresh? | As old as the last training run | As fresh as the page the bot reads |
| Can you see it? | No, only by asking the model | Yes, in server logs and cited sources |
| Can you change it fast? | No, it waits for the next model | Yes, edit the page and wait for a recrawl |
| Best lever | Consistent public mentions over time | Clear answer pages that bots may read |
Which AI crawlers should you allow?
Allow the search and user bots, and decide separately about the training bots. OpenAI, Anthropic and Google each split their crawlers by purpose, so one robots.txt line can block training without hiding you from answers. OpenAI recommends allowing OAI-SearchBot, and says sites that opt out of it will not appear in ChatGPT search answers, though they can still appear as a navigational link 3.
Blocking training bots is a business choice, not a visibility fix. Cloudflare measured AI crawling over 12 months to mid-2025 and found 80% of it was for training, 18% for search and 2% for user actions 4. So across Cloudflare's network most AI crawler traffic is training collection. Check which bot made each visit in your own logs before you read a visit as a sign of citation.
Robots.txt changes are not instant. OpenAI says its search systems can take about 24 hours to adjust 3. Also, user-triggered fetchers such as ChatGPT-User may not follow robots.txt rules, because a person asked for the page 3.
| Bot | Company | Purpose | Source |
|---|---|---|---|
| GPTBot | OpenAI | Content that may train foundation models | OpenAI docs 3 |
| OAI-SearchBot | OpenAI | Surfaces sites in ChatGPT search | OpenAI docs 3 |
| ChatGPT-User | OpenAI | Visits triggered by a user action | OpenAI docs 3 |
| ClaudeBot | Anthropic | Collects content that could contribute to training | Anthropic help 5 |
| Claude-User | Anthropic | Fetches pages when a user asks Claude | Anthropic help 5 |
| Claude-SearchBot | Anthropic | Improves search result quality | Anthropic help 5 |
| Google-Extended | Training and grounding for Gemini; no effect on Google Search | Google docs 6 |
Do brand mentions across the web change what models say?
Brands that are mentioned more across the web also tend to appear more in AI answers, but this is correlation, not proof. Ahrefs studied 75,000 brands and found branded web mentions correlated with AI visibility at roughly 0.66 to 0.71, and YouTube mentions at about 0.737 7. Ahrefs itself warns that correlation is not causation.
The sample only covers domains with a Domain Rating above 40, so it says little about small or new sites 7. Google adds a caution for its own search: seeking inauthentic mentions across the web is not as helpful as it might seem 8. Real mentions come from real work: customers, press, reviews, talks and useful content.
For LLMO this is the nearest thing to a training-memory lever. Be described the same way in many independent places, and keep your name, offer and facts consistent.
Does llms.txt count as LLMO?
It is often sold as LLMO, but the evidence is thin: Google says Google Search ignores the file, and a large SE Ranking study found no link to AI citations. Our full explainer is at What is llms.txt?, and the free llms.txt generator builds one in minutes.
Six Claude searches for one LLMO question
We put 'what is LLM optimization LLMO' to Gemini and Claude on 2026-10-20 and logged every web search each one ran. Gemini ran two short searches. Claude ran six, and they split the topic into definition, citation, llms.txt, comparison, crawlers and training versus retrieval.
That split is useful. A page that answers only the definition meets one of six searches. This page tries to cover the others as separate, quotable sections.
| Engine | Search it ran |
|---|---|
| Gemini | LLM optimization |
| Gemini | LLMO definition |
| Claude | what is LLM optimization LLMO |
| Claude | LLMO how to get cited by ChatGPT |
| Claude | llms.txt does it work |
| Claude | LLMO vs GEO vs SEO difference |
| Claude | allow GPTBot OAI-SearchBot robots.txt AI crawlers |
| Claude | LLM brand mentions training data vs retrieval RAG |
What does an LLMO-minded robots.txt look like?
This example keeps you visible in AI search and opts out of training collection by two vendors. It follows the bot purposes in the table above. Check each vendor's current documentation before you copy it, because bot names change.
Treat it as one option. Some businesses allow all of these bots, since being known by models is the goal. Blocking training is a legal or commercial preference, and it does not change what live search sees.
- # Allow bots that power AI search and user requests
- User-agent: OAI-SearchBot
- Allow: /
- User-agent: Claude-SearchBot
- Allow: /
- # Opt out of training collection
- User-agent: GPTBot
- Disallow: /
- User-agent: ClaudeBot
- Disallow: /
How can you apply LLMO this week?
Start with the live-lookup route, because you can measure it. Each step below takes under an hour.
- Run the free AI crawler checker and confirm that search bots can reach your key pages.
- Write one plain paragraph that states what you sell, for whom and where. Use the same wording on your site, LinkedIn and directory listings.
- Ask ChatGPT, Claude and Gemini the five questions a buyer would ask, and save the answers with the date.
- Fix any wrong fact the assistants repeat. Start at the source page they cite, using our guide to fixing wrong AI answers.
- Use the query fan-out explorer to see which sub-questions an assistant searches, then write one page for each.
What an AI assistant searches when it answers this
We gave the question below to AI search tools and recorded the web searches they ran behind the scenes. This is called query fan-out. Each phrase is a page you could publish to be found and cited.
“what is LLM optimization LLMO”
The searches it ran- what is LLM optimization LLMO
- LLMO how to get cited by ChatGPT
- llms.txt does it work
- LLMO vs GEO vs SEO difference
- allow GPTBot OAI-SearchBot robots.txt AI crawlers
- LLM brand mentions training data vs retrieval RAG
- LLM optimization
- LLMO definition
Frequently asked questions
Is LLMO the same as GEO?
Nearly. GEO focuses on being cited inside generated answers, while LLMO adds the idea of the model's own training memory. In daily work the tasks overlap: clear pages, open crawler access and consistent mentions. See our comparison of GEO and LLMO.
Can I get my business into an LLM's training data?
Not on demand. Training data comes from past web crawls, and vendors do not take submissions. What you can do is publish clear public pages and earn consistent mentions. We found no reliable study showing how much any single brand's content shifts a model's trained knowledge.
Should I block GPTBot?
That depends on your view of training use, not on search visibility. OpenAI says disallowing GPTBot signals content should not be used for training, while OAI-SearchBot is the agent tied to ChatGPT search 3. Many sites block one and allow the other. Decide with your lawyer if content rights matter.
Does llms.txt improve LLM visibility?
How do I know if an AI model describes my business correctly?
Ask it. Run the same buyer questions in ChatGPT, Claude and Gemini each month, and record whether you are named, how you are described and which sources are cited. Our brand audit guide walks through the process.
Sources
- Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks · arXiv (Lewis et al.; NeurIPS 2020)Opened October 20, 2026. Supports: Defines retrieval-augmented generation as combining pre-trained parametric memory with non-parametric memory accessed by a retriever.
- Web search tool · Anthropic (Claude developer documentation)Opened October 20, 2026. Supports: Describes the Claude API web search tool: Claude searches when a request depends on information that is current, changing or outside its training data, including specific organisations, people or products that might have changed; answers cite sources.
- Overview of OpenAI Crawlers · OpenAIOpened October 20, 2026. Supports: GPTBot is for content that may train models; OAI-SearchBot surfaces sites in ChatGPT search and is recommended; sites that opt out of OAI-SearchBot will not appear in ChatGPT search answers but can still appear as a navigational link; about 24 hours for robots.txt changes; ChatGPT-User visits are user-initiated and robots.txt may not apply.
- The crawl-to-click gap: Cloudflare data on AI bots, training, and referrals · Cloudflare BlogOpened October 20, 2026. Supports: Over the 12 months to mid-2025, 80% of AI crawling was for training, 18% for search and 2% for user actions (published 29 August 2025; classification is Cloudflare's).
- Does Anthropic crawl data from the web, and how can site owners block the crawler? · Anthropic SupportOpened October 20, 2026. Supports: ClaudeBot collects content that could contribute to training; Claude-User fetches pages when users ask; Claude-SearchBot improves search result quality.
- Google's common crawlers · Google Search CentralOpened October 20, 2026. Supports: Google-Extended is a standalone product token for Gemini training and grounding, does not affect Google Search inclusion, and has no separate HTTP user-agent string.
- AI Brand Visibility Correlations (75K brands) · AhrefsOpened October 20, 2026. Supports: Branded web mentions correlate with AI visibility at about 0.66 to 0.71; YouTube mentions about 0.737; sample filtered to DR above 40; correlation is not causation (published 12 December 2025).
- Optimizing your website for generative AI features on Google Search · Google Search CentralOpened October 20, 2026. Supports: Google Search ignores llms.txt, which neither helps nor harms; seeking inauthentic mentions is not as helpful as it might seem (last updated 2026-07-10).
- LLMs.txt study · SE RankingOpened October 20, 2026. Supports: About 300,000 domains analysed; no correlation between llms.txt and AI citation frequency (published 15 October 2026; method details such as engines sampled are not disclosed).