SEO vs GEO: What’s the Difference, and Which Should You Do First?

SEO gets your pages ranked in search results so people click through to your website. GEO, or generative engine optimisation, gets your brand mentioned, cited and recommended inside the answers AI tools write, often without a click. The two aren’t rivals. GEO depends on the crawlable, trusted pages that SEO builds, so most businesses should fix their SEO first and add GEO on top. There are a few exceptions, and we’ll cover them.

That’s the short version. The longer one matters because businesses are being sold SEO and GEO as competing products, and a lot of budget is going to the wrong one. At Castle, our SEO agency and GEO agency teams work as one programme for exactly that reason. This guide compares the two side by side, explains what has really changed in search since 2023, answers the related question of AI SEO vs traditional SEO, and ends with a plain recommendation on where to start.

What’s the difference between SEO and GEO?

The core difference is the outcome. SEO aims for a position on a results page and the click that follows. GEO aims for a mention or citation in a generated answer, where there may be no click at all.

Ask Google “best accounting software for freelancers” and SEO decides whether your page sits first, third or on page two. Ask ChatGPT the same thing and it might name three products with a sentence on each. GEO decides whether yours is one of the three, and whether the sentence about it is accurate.

The table makes them look further apart than they are. A page that ranks well usually has exactly what an AI system looks for: it’s crawlable, clear and covers the topic properly. For the full definition of the newer discipline, read what GEO is.

Where do SEO and GEO overlap?

SEO and GEO overlap on almost every input. They differ mainly in output and measurement, which is why we’d never staff them as separate teams.

Crawling and indexing. Google says there are no additional requirements to appear in AI Overviews or AI Mode: a page simply has to be indexed and eligible for a snippet. ChatGPT needs its search crawler allowed in, and OpenAI says that’s how a site becomes eligible for ChatGPT search. Either way, if a crawler can’t reach the page, it doesn’t exist.

Helpful content. Both reward content that answers the real question with something original. Google’s advice for AI search is to create unique, non-commodity content, which is the same thing it has been saying about classic search for years.

Authority. Links, reviews, expert authorship and press coverage build trust with both. GEO leans harder on mentions, but it doesn’t throw links away.

Site structure. Internal links help crawlers and AI systems connect related pages, which matters more now that Google’s AI features use query fan-out to run several related searches behind one question.

Where is GEO genuinely different from SEO?

GEO is different where the output is a generated conclusion rather than a list of options. Four differences matter in practice.

The answer is the destination

A results page hands the user ten options to choose from. An AI answer makes the choice for them, or at least narrows it to two or three. Your brand can shape the decision without anyone visiting your site, so traffic alone undercounts GEO’s value.

Ranking well doesn’t guarantee being cited

This is the difference that surprises people most. Semrush found that when ChatGPT search cites a web page, that page ranks in position 21 or lower for related queries almost 90% of the time. AI systems pick passages, not whole pages, so a sharp answer buried on a page-three result can beat a vague one in position one. The reverse is also true: you can rank first and still be left out of the answer.

Off-site reputation carries more weight

AI systems form a view of your brand from everything said about it. In Ahrefs’ study of 75,000 brands, branded web mentions correlated three times more strongly with AI Overview visibility than backlinks, at 0.664 against 0.218. That’s correlation rather than proof, but it moves digital PR and review management from “nice to have” to central.

Accuracy becomes something you manage

In classic SEO, Google shows your title and meta description, which you wrote. In GEO, the AI writes its own summary of you. If your website says one thing and an old directory listing says another, the answer may repeat the wrong one. Checking how you’re described becomes part of the job.

What has actually changed in search since 2023?

Three things changed between 2023 and 2026, and only the first gets most of the attention.

AI answers now sit above the results. Google’s AI Overviews summarise an answer before the organic listings, and AI Mode, which launched in the UK in July 2025, turns the whole page into a conversation. Ofcom reports that about 30% of UK searches now show an AI overview.

Queries got longer and more conversational. People type questions they’d ask a colleague. Google notes that users ask longer, more specific questions and follow-ups in AI search. This is the change with the biggest effect on how pages should be written, and the least discussed.

Search went from lists to shortlists. Assistants now recommend two or three options and explain why. The job shifted from “rank for the query” to “be the recommendation for the question”.

Clicks are where it hurts. Pew Research Center found that people who saw an AI summary on Google clicked a traditional result in 8% of visits, against 15% without one. Ahrefs’ 2026 update found AI Overviews reduce the click-through rate for the top result by 58%.

Which SEO signals still count, and what stopped working?

Most of the SEO fundamentals still count. What stopped working is mostly the stuff that was already a bit dodgy.

Still counts

• Crawlability and indexation. AI can’t quote what it can’t reach. Security plugins and CDN settings that block AI crawlers quietly remove you from those answers.
• Backlinks, as credibility rather than votes. Relevant links from trusted sites still matter. Volume for its own sake matters less.
• Topical authority. Several connected pages covering a subject properly beat one heavily optimised page.
• Research, reframed. Keyword research still matters, but you’re now also researching the questions and prompts people type.
• Page experience. Google tells site owners to give visitors from AI and classic results alike a good page experience.

Stopped working

• Keyword density. In the original GEO research paper, keyword stuffing performed slightly worse than leaving the page alone.
• Thin content at volume. Google’s spam policies call mass-produced, unoriginal pages scaled content abuse, however they’re made. AI systems have no reason to quote them either.
• Keyword-rich anchor text at scale. The same spam policies list keyword-rich and optimised anchor links in guest posts and press releases as link spam.
• Writing for the crawler. If a sentence reads oddly to a person, it won’t impress an AI system that learned from how people write.

Does SEO still work in 2026?

Yes. Anyone telling you SEO is dead is usually selling you the replacement. Google is still used by 82% of UK adults, according to Ofcom, and Sundar Pichai said in July 2026 that AI Mode is driving an incremental increase in Search queries overall, with Google sending billions of clicks to websites every week through its AI features.

What changed is what a good ranking delivers. It used to deliver a click. Increasingly, it delivers a citation in an AI answer instead, plus fewer but better-qualified visits. Google says clicks from results pages with AI Overviews are higher quality, meaning people spend longer on the site.

That creates a measurement trap. Sessions can fall while your visibility grows, because people read your answer in the summary rather than on your page. If you judge SEO on traffic alone in 2026, it can look like it’s failing when it’s doing its job.

AI SEO vs traditional SEO: is that the same comparison?

Not quite. Traditional SEO is about ranking in search results. AI SEO is the umbrella that keeps those SEO foundations and adds both GEO and answer engine optimisation (AEO), measured across normal search and AI answers together. So “AI SEO vs traditional SEO” is really asking what you add to SEO, not what you swap it for.

Traditional SEO covers the familiar work:

• Technical SEO, so pages are crawled and indexed
• Keyword research and on-page optimisation
• Site architecture and internal linking
• Helpful content that matches search intent
• Link building and digital PR
• Local, ecommerce or international SEO, where relevant
• Reporting on rankings, traffic and revenue

AI SEO keeps all of that and adds:

• Access for AI search crawlers, tested rather than assumed
• Answer-ready passages that work when lifted out of context
• A consistent brand description everywhere AI systems look
• Third-party corroboration of the claims you make about yourself
• Tracking of mentions, citations and accuracy across platforms

If you want the full picture of the umbrella term, read what AI SEO is. For the question-answering layer specifically, our AEO guide explains how it fits.

What does the difference look like for a real business?

Take an illustrative example: a 15-person accountancy firm in Manchester that wants more contractor clients. The numbers below are made up to show the mechanics, not drawn from a client.

The SEO view. The firm ranks fourth for “contractor accountant Manchester”. That keyword brings it around 120 visits a month and four or five enquiries. SEO work, such as a better service page, a few strong guides on IR35 and some local links, aims to move it into the top three and lift those visits.

The GEO view. A contractor opens ChatGPT and asks, “I’m a software contractor in Manchester outside IR35, which accountants should I look at, and what should I pay?” The answer names three firms and gives a fee range. GEO asks whether our firm is one of the three, whether its fees are described correctly and whether a link appears. None of that shows up in a ranking report.

Where they meet. The IR35 guide the SEO team writes is exactly the sort of specific, sourced page the AI answer draws on. The reviews and the mention in a contractor trade publication that GEO chases also help the service page rank. Same work, two scoreboards. That’s why splitting SEO and GEO into rival projects usually wastes money.

SEO or GEO: which should you do first?

Almost always, SEO first. GEO needs the foundations SEO lays: pages AI systems can crawl, content worth quoting and enough authority to be trusted. Optimising for citations on a site that can’t be crawled properly is like rehearsing a speech for a room nobody can get into.

Our work with HNK Solicitors shows the order in action. The Liverpool firm came to us spending around £30,000 a month on Google Ads. Seven years of SEO built the crawlable site, deep topical coverage and established rankings. When we started tracking its AI citations in January 2026 there were 38. By August 2026 there were 163, according to Ahrefs. That growth came because the SEO groundwork was already there, not from bolting an AI project onto the account. AI volumes are still small, and HNK’s case study says so plainly.

There are three exceptions where GEO should move up the list:

• Your rankings are stable but traffic is falling. You’re visible, but people are reading summaries instead of clicking. GEO helps you control what those summaries say.
• Your buyers ask AI for recommendations. In categories where people ask “who should I use for…”, being in the shortlist is the whole game.
• Competitors appear in AI answers and you don’t. That’s a gap SEO alone may not close, especially if it comes from off-site reputation.

How should you split your budget between SEO and GEO?

Treat GEO as part of your search budget, not a new line competing with it. Most of the work overlaps, so the real question is how much of your existing effort goes on GEO-specific tasks: entity clean-up, digital PR, answer formatting and AI visibility tracking.

How we’d think about it:

• Weak foundations (indexing problems, thin service pages, little content): put nearly everything into SEO. GEO tactics won’t stick yet.
• Solid SEO, little off-site presence: keep SEO going and shift effort towards digital PR, reviews and a consistent brand description.
• Strong SEO, falling clicks: move more effort into GEO and measure it properly, because that’s where your visibility is going.

Be wary of anyone who wants to sell GEO as a separate retainer while your site still has basic SEO problems. You’d be paying twice for the same foundations.

How do you measure SEO and GEO side by side?

Measure both against the same business outcome, which is qualified enquiries and revenue, then use channel-specific signals to explain what moved.

Two practical notes. Google counts AI Overviews and AI Mode inside the normal Web data in Search Console, so you can’t separate them there. Bing is ahead on this: its AI Performance report shows which of your pages are cited in Copilot and Bing’s AI answers. And ask new enquiries how they found you. “ChatGPT recommended you” is turning up on enquiry forms more often than most dashboards suggest.

What does a combined SEO and GEO plan look like?

A combined plan does the SEO groundwork and the GEO layer together, on the same pages, with one set of reports.

• Publish fewer, better pages with more depth and real expertise
• Open every important page and section with a direct answer
• Use one consistent brand description, with accurate schema and matching business details everywhere
• Invest in digital PR and earned media, not just links
• Keep the technical basics clean, including AI crawler access
• Track prompts and citations alongside rankings
• Review AI visibility every quarter, not once a year

Our complete guide to AI SEO and GEO turns this into a 90-day plan.

FAQs

Is GEO replacing SEO?

No. AI search tools retrieve their sources from crawled, indexed pages, so SEO remains the foundation. GEO adds a second goal on top: being cited and recommended accurately inside AI answers, not just ranked beneath them.

Is GEO better than SEO?

Neither is better; they do different jobs. SEO wins positions and clicks, and GEO wins mentions in AI answers. For most businesses, GEO only works well once SEO is in good shape, so the useful question is the order, not the winner.

Can you do GEO without SEO?

Partly. You can tidy your brand description and earn third-party mentions without touching your site. But if AI crawlers can’t reach your pages, or your content is thin, there’s little for AI systems to cite. The two work best as one programme.

How long do SEO and GEO take to work?

SEO typically takes months to show meaningful ranking gains, depending on competition and your starting point. Some GEO changes, such as unblocking crawlers or restructuring answers, can show up within weeks; authority and entity work takes months. Nobody can promise a timescale for either.

Do backlinks still matter for GEO?

Yes, but differently. Links from relevant, trusted sites act as credibility references for AI systems. Unlinked brand mentions on trusted sites appear to matter at least as much, so digital PR and reviews deserve a bigger share of attention than they had in link-led SEO.

Is AI SEO the same as GEO?

No. GEO is one part of AI SEO. AI SEO combines traditional SEO, answer engine optimisation and GEO into one programme, measured across both search results and AI answers.