AEO vs SEO: what's the difference, and do you need both?
They share most of the same work but aim at different prizes. Here is how answer engine optimisation and search engine optimisation differ, and how to decide where to spend your effort.
SEO optimises for ranking a page so people click it. AEO optimises for being cited inside an AI-generated answer. They overlap heavily, because clean structure, schema, freshness and authority help both, but a page can rank well and still be absent from AI answers. For most sites you need both, with SEO as the foundation and AEO built on top.
The core difference
For two decades the goal of search optimisation has been to climb a list. You wanted your page in the first few results, because that is where the clicks are. Search engine optimisation is the craft of earning that position.
Answer engines change the shape of the goal. When someone asks ChatGPT or Perplexity a question, or reads a Google AI Overview, there is often no list to climb. There is a single written answer, drawn from a few sources the engine has chosen to trust and cite. Answer engine optimisation is the craft of being one of those cited sources. The difference, in a sentence, is rank versus cite.
Where they overlap
It is easy to oversell AEO as something exotic. Most of it is not. The work that makes a page rank well, clear writing, a sensible heading structure, fast and crawlable pages, valid schema, genuine authority and freshness, is also the work that makes a page easy for an answer engine to read, trust and quote. If you do SEO properly, you have already done most of AEO.
There is one case where they are nearly the same thing. Google has said plainly that optimising for its own AI features is still optimising for Search, because those features draw on the same index and ranking systems as normal results. So for Google's AI Overviews and AI Mode, strong SEO is most of the job.
Where they diverge
The differences show up at the edges, and they matter.
| SEO | AEO |
|---|---|
| Earns a ranked position | Earns a citation in the answer |
| The reader picks from a list | The engine picks for the reader |
| A crawler reads, then ranking decides | Content is retrieved, summarised and attributed |
| JavaScript is usually rendered by Google | Many AI crawlers do not run JavaScript at all |
| Measured by position and clicks | Measured by mentions and citations |
The JavaScript line is the one that quietly catches people. Google generally renders pages, so a JavaScript-heavy site can still rank. Several AI crawlers do not render at all, so the same site can be invisible to them. A page can therefore pass SEO and fail AEO for a purely technical reason. We cover that in detail in is your website invisible to AI.
Do you need both?
For most sites, yes, and in that order. AEO sits on an SEO foundation. If your pages are not crawlable, indexable and well-structured, there is nothing for an answer engine to retrieve in the first place. You rarely do meaningful AEO without doing the SEO underneath it. The useful way to hold it in your head is that AEO is an extension of SEO, not a rival to it.
How to measure each
SEO has mature measurement: rankings, impressions, clicks and organic traffic, mostly through Google Search Console. AEO measurement is younger and messier. You are trying to track how often your brand and pages are mentioned or cited across AI answers, and because those answers are non-deterministic, the same question can return different sources from one run to the next. That means measuring trends across many runs rather than trusting a single snapshot, and treating each engine as its own channel. Be sceptical of any tool that promises one tidy universal AEO score.
Which to prioritise
Start with the SEO foundation, because it pays off in both worlds at once. Get the site crawlable, indexable, fast and well-structured. Then layer on the AEO-specific work: answering questions directly near the top of the page, making your entities and authorship clear, and earning authentic mentions across the web. If you want the full picture of what AEO involves, start with what is AEO, then work through how to get cited by AI answer engines.
Frequently asked questions
Is AEO replacing SEO?
No. AEO is best seen as an extension of SEO, not a replacement. For Google's own AI features the work is still largely SEO, because they draw on the normal Search index. AEO adds signals aimed at non-Google engines like ChatGPT and Perplexity.
Do I need to do both AEO and SEO?
For most sites, yes, but in order. A solid SEO foundation (a crawlable, indexable, well-structured site) is what AEO is built on, so you rarely do meaningful AEO without doing SEO first. The two share most of the same work.
How do I measure AEO compared to SEO?
SEO is measured by rankings, clicks and organic traffic, usually via Google Search Console. AEO is measured by how often your brand and pages are mentioned or cited in AI answers, which means tracking responses across engines over many runs, since those answers are non-deterministic.
Which should I prioritise first?
Prioritise the SEO foundation first, because it underpins both. Once your content is crawlable, indexable and well-structured, the AEO-specific work adds the most value on top.
Adam Clarke
Adam is a Chartered Marketer and Fractional CMO with over seventeen years in B2B and B2C marketing, and the founder of Rank Roadie. He writes about the messy overlap between search, AI and keeping humans accountable in the loop.