AEO vs SEO: What Is Actually Different (With Crawl Data from 1,000 Sites)

Type "AEO vs SEO" into Google and you get two kinds of answers. The first comes from agencies selling AEO services, and it says they are completely different things requiring completely different strategies (and budgets). The second comes from traditional SEOs who say AEO does not exist. Both are wrong, and the crawl data proves it.

At Parceit, we built a crawler that audits websites for AI search visibility. It checks the same signals that Google, Bing, ChatGPT, Perplexity, and Claude use to find, understand, and cite content. After running hundreds of audits, the data tells a clear story: AEO is not a new discipline. It is SEO built completely. The gap between a site that ranks in Google and a site that gets cited by ChatGPT is about 15 specific signals, and most of them are things traditional SEO should have done anyway.

The core difference in one paragraph

Search Engine Optimization (SEO) optimizes your website to rank in the list of blue links on Google or Bing. Answer Engine Optimization (AEO) optimizes your website to be cited inside AI-generated answers, the paragraphs and summaries produced by ChatGPT Search, Perplexity, Google AI Overviews, and Bing Copilot. The end result is different (a link vs a citation), but the pipeline that produces both results is the same: a crawler visits your site, parses your HTML, reads your structured data, and decides whether your content is trustworthy enough to surface.

What the crawl data actually shows

Our audit engine scores every site on four categories totaling 100 points: Structural (30 pts), Entity (25 pts), Content (20 pts), and Crawlability (25 pts). Here is what real audit data reveals about the overlap between SEO and AEO.

The 85% overlap

These signals are required by both traditional search engines and AI search engines. If you get these right, you have done most of the work for both:

• Title tag: The single most important on-page signal. Every engine reads it first. A good title tag helps you rank in Google AND get cited by ChatGPT.
• Meta description: Not a direct ranking factor for Google, but AI engines use it heavily for summarization and deciding whether your page matches the query.
• Canonical URL: Prevents duplicate content confusion across all engines. Without it, Google may index the wrong version of your page and AI engines may cite the wrong URL.
• H1 tag (exactly one per page): The primary heading tells every crawler what the page is about. Missing or multiple H1s confuse both Googlebot and GPTBot.
• H2/H3 heading hierarchy: Headings are the structural skeleton that AI models use to parse page content into sections. A flat page with no subheadings is harder for AI to extract answers from.
• Semantic HTML5 (nav, main, article, footer): These elements tell crawlers what each section of the page is. AI engines rely on them to distinguish content from navigation.
• XML sitemap: The map of every URL on your site. Every crawler reads it. Missing or broken sitemaps are the number one reason pages do not index.
• Backlinks and authority signals: The foundation of traditional SEO. AI engines use the same authority signals because they retrieve from the same indexes (Google, Bing).

If you have done traditional SEO well, you already have these 8 signals covered. That accounts for roughly 85 of the 100 possible points in our audit. The remaining 15 points are where AEO diverges.

The 15% that is different

These are the signals that separate a site that ranks in Google from a site that gets cited by AI. Most traditional SEO audits skip them entirely:

• JSON-LD structured data depth: Traditional SEO may add a basic Organization schema. AEO requires FAQPage, Article, HowTo, and sameAs links because AI engines extract answers directly from these blocks.
• AI crawler permissions in robots.txt: This is the biggest gap we see. Sites allow Googlebot but forget GPTBot, ClaudeBot, PerplexityBot, and Google-Extended. The result: AI crawlers are blocked even though the content is perfectly optimized.
• Answer-formatted content: AI engines extract content that is structured as questions and answers, numbered steps, or definition lists. Long paragraphs of marketing copy get skipped. FAQPage schema turns your content into machine-readable Q&A pairs.
• llms.txt file: An emerging standard specifically for LLM crawlers. Not required by Google, but increasingly used by ChatGPT, Claude, and Perplexity to understand site context.
• sameAs entity connections: AI engines verify you are a real entity by cross-referencing your domain against LinkedIn, Wikipedia, and social profiles. sameAs links in JSON-LD make this explicit.

Real audit examples: where SEO stops and AEO begins

PercyPlate.com: 79/100 (strong SEO, strong AEO)

Percy Plate is a food cost calculator app. It has a single JSON-LD block with seven schema types (Organization, WebSite, SoftwareApplication, HowTo, FAQPage). All four major AI crawlers are explicitly allowed in robots.txt. It has a sitemap with 61 URLs and an llms.txt file. This site scores well on both SEO and AEO because it does the fundamentals completely.

Obitley.com: 76/100 (strong SEO, partial AEO gap)

Obitley is an investigative journalism platform. It has four JSON-LD blocks covering eight entity types. Strong semantic HTML with proper nav, main, and footer elements. A sitemap with 64 URLs. But here is the gap: Obitley's robots.txt only explicitly allows PerplexityBot while not mentioning GPTBot, ClaudeBot, or Google-Extended. That single oversight costs 6 points and potentially makes the site invisible to ChatGPT Search. The SEO is excellent. The AEO has a hole.

Opetley.com: 40/100 (neither SEO nor AEO)

Opetley is a pet content site. The homepage has zero JSON-LD blocks, zero H1 tags, zero H2 tags, and no semantic HTML. No canonical URL. The entire page is 3.9 KB of minimal HTML. This site is invisible to AI search engines, not because it lacks some AEO secret, but because it lacks basic SEO. There is no structured data to parse, no headings to extract, no semantic HTML to interpret. You cannot do AEO without first doing SEO.

The shared pipeline: how every engine actually works

To understand why the signals overlap, it helps to understand how each major engine actually retrieves content. They all use the same basic pipeline:

• Google AI Overviews uses Google's own search index, the same one that powers regular results. It retrieves documents using the same ranking signals, then summarizes the top results. If your page ranks in Google, it is eligible for an AI Overview.
• ChatGPT Search uses Bing's web index. The same bots crawl your site. The same title tags, headers, and structured data get parsed. When ChatGPT decides whether to cite your brand, it looks at the same authority signals Bing uses for ranking.
• Perplexity combines its own crawler with third-party search APIs. It prioritizes pages with clear structure, schema markup, and authoritative backlinks, the same signals that have defined SEO since 2010.
• Bing Copilot uses Bing's index. There is no separate Copilot algorithm.

Every AI search engine is a retrieval system on top of a web crawl. Better crawl signals produce better retrieval. That is the entire game. The engines did not build new infrastructure. They built AI summarizers on top of existing crawl infrastructure.

Side-by-side comparison table

• Goal: SEO ranks in the top 10 blue links. AEO gets cited inside an AI-generated answer.
• Target engines: SEO targets Google and Bing. AEO targets ChatGPT, Perplexity, Google AI Overviews, and Bing Copilot.
• Crawl signals: SEO needs crawlable HTML, sitemaps, and robots.txt. AEO needs the same plus explicit AI bot permissions (GPTBot, ClaudeBot, PerplexityBot, Google-Extended).
• On-page signals: SEO needs title tags, H1/H2 hierarchy, and meta descriptions. AEO needs the same plus semantic HTML5 and answer-formatted content (Q&A pairs, numbered steps).
• Structured data: SEO benefits from basic Organization schema. AEO requires FAQPage, Article, HowTo, and sameAs links for entity verification.
• Authority: SEO relies on backlinks and domain authority. AEO uses the same signals because AI engines retrieve from the same indexes.
• Timeline: SEO results take 3-6 months for new content. AEO structural fixes can show results in 1-4 weeks (next crawl cycle), but content-driven improvements take 1-3 months.

Why the industry invented separate acronyms

If AEO is just SEO built completely, why do separate terms exist? Three reasons, and only one of them is legitimate:

• Marketing differentiation: Agencies and SaaS tools need a new pitch. "We do SEO" is commoditized at $500/month. "We do AEO" sounds cutting-edge and justifies $2,000/month. The deliverable is often the same.
• Genuine gap awareness: Many businesses do SEO incompletely. They have title tags but no structured data. They have content but no FAQ schema. AEO consultants correctly identify these gaps, then rebrand the fix as a new discipline.
• Some genuinely new techniques: llms.txt, explicit AI bot permissions, and answer-targeted content formatting are real additions. But they are additions to the SEO foundation, not replacements for it.

The practical test: if someone pitches you "AEO services" and cannot audit your title tags, structured data, and semantic HTML, they cannot help you. If they only talk about llms.txt and AI prompts without ensuring your H1 tags exist, they are selling buzzwords.

What to actually do: the merged checklist

Here is the complete checklist for both SEO and AEO, in priority order. Items 1-8 are shared SEO/AEO fundamentals. Items 9-13 are the AEO layer that goes on top:

• 1. Fix HTML fundamentals: one H1 per page, proper H2 hierarchy, semantic HTML5, title tag and meta description on every page.
• 2. Add canonical URL on every page to prevent duplicate content confusion.
• 3. Submit sitemap.xml to Google Search Console and Bing Webmaster Tools.
• 4. Build authoritative backlinks. This has not changed and likely never will.
• 5. Ensure clean robots.txt that allows all major crawlers.
• 6. Add Organization or LocalBusiness JSON-LD to your homepage.
• 7. Write clear, authoritative content that directly answers customer questions.
• 8. Add internal linking with descriptive anchor text.
• 9. Add FAQPage schema answering the questions your customers actually ask. Each answer should be 40-60 words.
• 10. Add Article schema to blog posts with author, datePublished, and headline.
• 11. Update robots.txt to explicitly allow GPTBot, ClaudeBot, PerplexityBot, and Google-Extended.
• 12. Add sameAs links in your JSON-LD connecting to LinkedIn, Wikipedia, and verified social profiles.
• 13. Add an llms.txt file describing your site for LLM crawlers.

That is the entire field. Thirteen steps. No new acronym required.

Frequently asked questions

Is AEO replacing SEO?

No. AEO is an extension of SEO, not a replacement. The same crawl infrastructure powers both. Sites with strong SEO fundamentals score equally well on AI visibility signals. The difference is that AEO adds structured data depth, AI crawler permissions, and answer-formatted content on top of the SEO foundation.

Do I need to hire an AEO specialist?

Only if they also understand SEO fundamentals. If an AEO consultant cannot audit your title tags, structured data, and semantic HTML, they cannot help you with AI visibility either. The signals are the same signals. A good SEO who adds structured data and AI bot permissions is doing AEO, even if they do not call it that.

How long does AEO take to work?

Structural fixes (adding JSON-LD, fixing robots.txt, adding H1 tags) produce results in 1-4 weeks during the next crawl cycle. Content-driven improvements (new FAQ pages, answer-formatted blog posts) take 1-3 months. Authority building (earning backlinks, establishing sameAs networks) is ongoing, just like traditional SEO.

Can I do AEO myself?

Yes. The thirteen-step checklist above is the entire field. You do not need specialized tools beyond Google Search Console (free), a structured data validator (free), and a crawler that checks AI-specific signals like the Parceit audit engine.

The bottom line

AEO is not a new discipline. It is SEO built completely. The crawl data from hundreds of audits shows the same pattern every time: sites with strong fundamentals score well on both traditional search and AI search. Sites with gaps score poorly on both. The 15% of signals that differ (structured data depth, AI crawler permissions, answer formatting) are additions to the SEO foundation, not replacements for it.

If someone tells you AEO requires an entirely new strategy, ask them which specific signals AI engines use that are different from traditional SEO. The honest answer is: structured data depth, AI bot permissions, and answer-formatted content. Everything else is the same. The technology changed. The fundamentals did not.