AEO vs GEO vs SEO: What's Actually Different, and What's Only a New Name
AEO vs GEO is mostly an argument about names. Answer engine optimization (AEO) and generative engine optimization (GEO) describe the same job: getting your brand into the answers AI search gives, and getting it described correctly. SEO is the older job both grew out of, and the line between all three is thinner than most comparison posts admit.
Google says so directly. Its guide to optimizing for generative AI search defines both terms, then adds: "From Google Search's perspective, optimizing for generative AI search is optimizing for the search experience, and thus still SEO." Below: what each term means, what the research behind GEO measured, and what holds up whatever you call the work.
AEO vs GEO vs SEO: three definitions
SEO: search engine optimization
Making pages that search engines can crawl, index and show. The target is a results page: a ranked list of links.
AEO: answer engine optimization
Work aimed at the answer rather than the list of links: Google's AI Overviews and AI Mode, ChatGPT search, Perplexity. We found no paper or standards body that defines AEO. It is an industry label with no fixed edges. Our answer engine optimization guide treats it as the answer-focused part of GEO.
GEO: generative engine optimization
Work aimed at answers written by a generative model. It is the only one of the three terms with a documented origin: a research paper. More in our guide to generative engine optimization.
Google defines the two newer terms together: "These are both terms you may see used to describe work specifically focused on improving visibility in AI search experiences." The same goes for newer labels such as LLM SEO.
Where the terms come from
GEO: a 2023 paper, and what it measured
"GEO: Generative Engine Optimization" was posted on 16 November 2023 by six researchers, including Pranjal Aggarwal and Karthik Narasimhan, and accepted at KDD 2024. Its abstract says GEO "can boost visibility by up to 40% in generative engine responses." Here is what was tested:
- The authors built the engine. "Only the top 5 sources are fetched from the Google search engine for every query", and gpt-3.5-turbo writes the answer.
- Every page tested was already a source. The authors "randomly select one source website to be optimized" per question.
- Visibility meant words, not visits. The main metric, Position-Adjusted Word Count, counts the answer's words in sentences citing that source, weighted by position.
- The live test used uploaded files. "Since perplexity.ai does not allow the user to specify source URLs, we instead provide source text as file uploads".
The headline result: three rewrites (citing sources, adding quotations, adding statistics) "achieved a relative improvement of 30-40% on the Position-Adjusted Word Count metric." Keyword stuffing, the old SEO trick, did not work.
The GEO paper measured which already-retrieved source gets quoted more. It did not measure whether a page gets found.
A larger benchmark tested the same family of rewrites. C-SEO Bench, accepted at NeurIPS 2025 Datasets and Benchmarks, found that "most current C-SEO methods are not only largely ineffective but also frequently have a negative impact on document ranking". What worked better: "traditional SEO strategies, those aiming to improve the ranking of the source in the LLM context."
The comparison: surface, control, measurement, evidence
| SEO | AEO | GEO | |
|---|---|---|---|
| Target surface | Search results: ranked links | Direct answers: AI Overviews, AI Mode, ChatGPT search, Perplexity | Any answer a generative model writes, with or without a live search |
| What you control | Crawl access, indexing, page content, links | The same, plus plain facts on pages AI can reach | The same for live search. Nothing for answers from memory |
| What can be measured | Rank, impressions and clicks in Search Console | Mentions and citations on a sample of prompts, plus Google's Generative AI performance report | Mentions, citations and accuracy on a sample of prompts |
| What has evidence | Google's published technical requirements | Access and eligibility rules from Google and OpenAI. No study of an AEO tactic | Lab tests rewriting pages already in the sources: +30-40% (2023), mostly no effect or worse (2025) |
What's actually different
Three things are new. None needs a new acronym.
- The output is an answer, not a list. An AI answer names a few brands, in an order, in its own words. Being named first, and named correctly, matters as much as a link.
- Some answers come from memory. OpenAI says ChatGPT "may search the web automatically when your question would benefit from current information." When it does not search, it answers from training, and nothing you publish this week reaches that answer until the next model.
- Measurement is a sample. ChatGPT search "typically rewrites your query into one or more targeted queries" before it searches. Any tool that tracks prompts, ours included, sees a stand-in for those queries, not the queries themselves.
What's only a new name
The levers with evidence behind them are the same under all three names. Each removes a reason to be left out. None adds a bonus.
Be reachable
Google's list starts with "Ensuring that crawling is allowed in robots.txt, and by any CDN or hosting infrastructure." OpenAI's rule for ChatGPT search: "To make a website eligible for inclusion, allow OAI-Searchbot to crawl the site and confirm that the website host or content delivery network allows traffic from OpenAI's published searchbot IP addresses." Which OpenAI crawler does what is in GPTBot vs OAI-SearchBot.
Be eligible
Google's page on AI features and your website: "To be eligible to be shown as a supporting link in AI Overviews or AI Mode, a page must be indexed and eligible to be shown in Google Search with a snippet, fulfilling the Search technical requirements. There are no additional technical requirements." A noindex or nosnippet tag takes you out, whatever you call the work.
Be right
Google's list includes "Making sure that important content is available in textual form" and "Making sure your structured data matches the visible text on the page." Put your prices and company facts on your own pages as plain text.
Google also lists what you can skip: "You don't need to create new machine readable files, AI text files, markup, or Markdown to appear in Google Search (including its generative AI capabilities), as Google Search itself doesn't use them." See the evidence on llms.txt and schema markup for AI.
Whatever the acronym, the work that survives scrutiny is the same: be reachable, be eligible, be right.
A five-step check that works under any name
- Read your robots.txt for each search crawler, starting with Googlebot and OAI-SearchBot. Blocking a training crawler is a separate decision.
- Request your key pages through your CDN as those crawlers. A firewall that returns 403 cancels a robots.txt allow.
- Check for noindex and nosnippet on every page you want quoted.
- Load your key pages with JavaScript off. If a price disappears, AI crawlers may miss it too. Vercel and MERJ found in 2024 that ChatGPT and Claude crawlers fetch JavaScript files but "don't execute them."
- Ask AI the questions your buyers ask, check every fact against your records, and note the date and model.
99Visibility runs the access and accuracy side of this for you. It audits five AI platforms (ChatGPT, Gemini, Perplexity, Google AI Overviews and Claude), tracks your competitors, checks the answers against the brand facts you enter, and checks whether AI crawlers can reach your site. Your first audit is free, with no credit card, and covers ChatGPT and Google AI Overviews. See the plans for all five platforms. Inside the dashboard, Agent V reads your audits and your site and drafts the fix, such as page copy for you to paste. It never edits your site itself.
FAQ
Is AEO the same as GEO?
In practice, mostly. Neither has a standard definition, and Google calls both SEO.
Is GEO replacing SEO?
Not on Google. A page must be indexed and snippet-eligible to appear as a link in AI Overviews or AI Mode. Our SEO vs GEO post covers how the day-to-day work changes.
Does GEO increase visibility by 40%?
Not in the sense most people mean. The figure measured words quoted from a page that was already one of five sources, not whether a page gets found or clicked.
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