CitationLab
Comparison

SEO vs AEO vs GEO vs LLMO

Published by Krister Ross · Updated May 2026

Four acronyms describe how brands get found in 2026, and they are easy to confuse. Here is what each one actually means, how they differ, and how to decide where to put your effort.

In short

SEO ranks links in traditional search. AEO is the work of becoming the brand AI assistants recommend in their answers. GEO is the work of being cited as a source inside generated answers. LLMO is the umbrella term for shaping how language models perceive your brand, and it contains both AEO and GEO. They are layers of the same problem, not competing choices, and in 2026 most brands need all four working together.

Read the complete AI visibility guide for the full picture.

The four disciplines side by side

The same brand can win or lose on each of these independently. The differences are easiest to see in one view.

SEOAEOGEOLLMO
FocusRanking links in search resultsBeing recommended in AI answersBeing cited as a source in answersHow models perceive your brand
PlatformsGoogle, BingChatGPT, Gemini, PerplexityAI Overview, Perplexity, ChatGPTAll major language models
Success metricPosition and organic clicksRecommendation rate and share of modelCitation rate and sources usedAccuracy and sentiment of the model view
Key leverContent, links, technical healthEntity authority and structured answersCitable, verifiable source contentA coherent, consistent brand identity
TimeframeMonths to compoundWeeks to monthsWeeks to monthsOngoing, builds over time

SEO ranks links in search

Search engine optimization is the oldest of the four. For two decades it has decided who appears when someone types a query into Google or Bing. The goal is a high position in a list of links, so the right page earns the click.

SEO rests on three fundamentals that have not changed: content that matches what people are looking for, technical health so the page can be crawled and rendered, and authority earned through links and reputation. These fundamentals still hold value, and they feed everything that comes after.

SEO works best when the buyer still clicks through to a website to compare and decide. For high-consideration purchases, local search and branded queries, that behaviour is far from gone, which is why SEO remains foundational rather than obsolete.

Platforms

Google, Bing

Success metric

Position and organic clicks

Key lever

Content, links, technical health

Timeframe

Months to compound

AEO earns the recommendation in AI answers

Answer Engine Optimization is the work of becoming the brand an AI assistant names when a customer asks for a recommendation. When someone asks ChatGPT or Gemini which tool, supplier or service they should choose, AEO decides whether your brand is in that short answer.

The mechanism is different from SEO. The assistant does not return a ranked list, it returns a judgement built from everything it has learned about the options. AEO works by building entity authority, a clear and verifiable identity, and structured content that answers the real questions buyers ask.

AEO matters most where the customer now resolves the decision inside the conversation and never reaches a list of links. That share of buying journeys is growing quickly, which is why AEO has become the highest-leverage new discipline.

Platforms

ChatGPT, Gemini, Perplexity

Success metric

Recommendation rate and share of model

Key lever

Entity authority and structured answers

Timeframe

Weeks to months

GEO gets you cited as a source

Generative Engine Optimization is the work of being used as a source inside a generated answer, the link or attribution that appears when an AI assistant or AI Overview backs up what it says. Where AEO is about being recommended, GEO is about being the reference the model leans on.

GEO rewards content that is genuinely citable, clear claims, verifiable facts, original data and a structure the model can lift cleanly into its answer. Being cited builds trust both with the reader who follows the link and with the model that learns to treat your domain as reliable.

GEO is most valuable for brands that publish substance, research, guides, documentation and primary information that others want to reference. A strong citation footprint reinforces AEO, because the brand a model cites is often the brand it goes on to recommend.

Platforms

AI Overview, Perplexity, ChatGPT

Success metric

Citation rate and sources used

Key lever

Citable, verifiable source content

Timeframe

Weeks to months

LLMO is the umbrella over all of it

Large Language Model Optimization is the broadest term of the four. It covers all the work of shaping how language models perceive your brand, what they know about you, how accurately they describe you, and whether they speak about you positively. AEO and GEO both sit inside LLMO.

Thinking in terms of LLMO keeps the goal honest. Being recommended and being cited are outcomes, but they rest on the model holding a correct, complete and favourable picture of who you are. If the model misunderstands your brand, no single tactic fixes it.

In practice LLMO is the layer where datadriven optimization happens. You measure how every major model perceives and mentions the brand, find the gaps and mistakes, and close them with the entity, content and citation work that AEO and GEO describe.

Platforms

All major language models

Success metric

Accuracy and sentiment of the model view

Key lever

A coherent, consistent brand identity

Timeframe

Ongoing, builds over time

What does your business need

A few guided questions point you to where the effort belongs first.

  • If buyers still compare options on websites before deciding, SEO remains foundational and should not be neglected.

  • If customers increasingly ask an assistant for a recommendation, AEO is the highest-leverage place to invest next.

  • If you publish research, guides or primary data, GEO turns that substance into citations that compound trust.

  • If models describe your brand inaccurately or barely know you exist, start with LLMO to fix the underlying picture.

  • If you are unsure, a visibility check shows what AI says about you today and which gap to close first.

In 2026 all four work together

These disciplines are layers of one problem, not a menu to choose from. SEO keeps your owned pages findable and healthy. GEO turns that content into citations the models trust. AEO converts that trust into recommendations. LLMO keeps the whole picture accurate and favourable.

A brand that treats them as competing tactics tends to win one and lose the rest. A brand that treats them as one system, built on a clear identity and substantive content, compounds across all four. The fundamentals overlap heavily, which is why the work pays off in more than one channel at once.

Read the complete AEO guide

Frequently asked questions

The questions we hear most about these four disciplines.

SEO optimises for ranking links in traditional search so a page earns the click. AEO optimises for being the brand an AI assistant recommends inside its answer. They share fundamentals like clear content and authority, but the goal differs: ranking a link versus being the recommendation.

GEO, or Generative Engine Optimization, is the work of being cited as a source inside generated answers. Where AEO is about being recommended, GEO is about being the reference an AI assistant or AI Overview links to when it backs up what it says.

LLMO, or Large Language Model Optimization, is the umbrella term for shaping how language models perceive your brand, how accurately they describe you and whether they speak about you favourably. Both AEO and GEO sit inside LLMO.

Most brands in 2026 need all four working together, but the starting point depends on you. If buyers still compare on websites, SEO stays foundational. If they ask assistants for recommendations, AEO has the highest leverage. A visibility check shows which gap to close first.

No. SEO is no longer the only discipline that decides who gets found, but its fundamentals of clear content, technical health and authority feed AEO and GEO directly. SEO is now the foundation that the AI-era disciplines build on rather than a standalone answer.

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See where you stand across all four

Most businesses have no idea how AI describes and recommends them. A free visibility check shows you how ChatGPT, Gemini and Google AI Overview see your brand right now, and which discipline to prioritise.