seo
How ChatGPT and Perplexity Decide Which Sources to Cite
AI Visibility Engineering
System track
Visibility engineering: SEO optimizes for rank, answer engines optimize for citation.
This track is the engineering playbook for the second game: entity coherence, schema specificity, originality signals, and the measurement loops that show whether ChatGPT, Perplexity, and Google AI Overviews are actually citing you.
Guided track Machine-readable 30 posts
Why this cluster exists
SEO optimizes for rank. Answer engines optimize for citation-worthiness. This cluster is the engineering playbook for the second game, sized for operators, not enterprise SEO teams.
System object
retrieval lattice
Best for
content engineers and sub-DR-20 operators engineering for AI citations
What visibility engineering means
Search engine optimization asks how a page ranks. Visibility engineering asks a different question: when an answer engine such as ChatGPT, Perplexity, Claude, or an AI Overview composes an answer, does it cite you, and can you prove it? The distinction matters because ranking signals and citation signals overlap less than most SEO advice assumes. This page is the reading order for the engineering side: crawler access, structured data, entity clarity, content shape, and the measurement that tells you whether any of it worked.
Start with how ChatGPT and Perplexity decide which sources to cite, the six measurable factors. Then Perplexity citation format versus ChatGPT for how the engines differ, and the 90-day roadmap for sub-DR-20 sites for the order of operations on a site without authority to spend.
The engineering framing is deliberate. Most writing about AI search treats citation as a content problem: write better, wait longer. The posts here treat it as a pipeline with observable stages. A crawler either reaches the page or it does not. The page either carries machine-readable structure or it does not. The entity either resolves to one thing across the web or it splits into three. An engine either names you or it does not, and that can be counted. Each stage has a test, each test has a fix, and the fixes are ordered by how often they turned a zero into a citation on real sites.
Why you are not being cited
The most useful posts in this track measure absence. Why ChatGPT is not citing your website asked three engines the 16 questions my buyers ask and counted how often my own site appeared. Five axes on a DR 25 site is the follow-up with 1,500 AI citations in 90 days and the five checks that produced them. My 0/5 GEO audit is the same method applied to buyer-intent queries on Perplexity, with a worse score and a clearer lesson.
The AI citation audit across 7 sites runs the ten infrastructure checks on sites other than mine and reports which three predicted citations. Why domain authority is irrelevant for AI search explains why the usual proxy does not transfer, and what a small site builds instead.
Read the absence posts before touching the infrastructure posts. The temptation is to start with schema and llms.txt because those are concrete edits. But a site that scores well on every infrastructure check and still earns zero citations has a different problem, usually entity confusion or a content shape the engines do not extract. The audit posts show how to tell which case you are in before spending a week on markup.
Crawler access and structured data
An engine cannot cite what it cannot read. llms.txt for AI crawlers covers the file that robots.txt does not replace, and Content Intent Signaling covers the directives that separate training access from answer access. Cloudflare will block AI crawlers by default on September 15 is the deadline post: what changes, and whether to block, allow, or charge.
Once the crawler is in, the page has to be legible as data. Schema.org for answer engines is the list of 40 properties that matter and the ones that do nothing. Entity optimization for brands and entity-level versus page-level SEO make the case that the unit of citation is the entity, not the URL, and show what changed when I switched.
Measuring citations
Citation counts live in places most dashboards ignore. Bing Webmaster Tools AI performance found roughly 1,200 Copilot citations hiding in a report nobody opens. Search Console generative AI report covers the report Google shipped and the three things it withholds.
Perplexity named zero brands, 40 answers in a row and the 47-answer recommendation study are category-level reads: whether the engines name anyone at all in your market, and how much they agree when they do. Who are the experts on AI search visibility? names the practitioner sources the engines already trust.
A word on what these numbers mean. A citation count is a snapshot of an engine on a day, not a rank. The same query asked twice can return different sources, and the counts across engines do not sum. The posts report the method with each number so you can rerun it on your own domain rather than compare against mine. Comparing two sites on different days with different query sets tells you nothing, which is why the audit posts fix the query list first.
Where this track leads
The free AEO audit runs the crawler and structured-data checks from this page against any URL and returns a pass or fail per check. For ongoing measurement across engines, the citability.dev link below is the tool I built for the job, and the two-domain split is deliberate: this site explains the engineering, that one measures the result.
Everything linked above stays free. New posts in this track go to the newsletter at the bottom of this page first.
Start here
The best first read in this track.
Core journey
Read these in order if you want the strongest mental model.
Foundation
AI Visibility Audit for B2B SaaS: Find Where Buyers See Competitors Instead
An AI visibility audit tells a B2B SaaS company which buyer questions ChatGPT, Perplexity and Google answer with a competitor, and whether the gap is worth fixing. Here is what a real one measures.
How to Choose the Best AI SEO Agency for B2B SaaS
There is no best AI SEO agency in the abstract. Here is the evidence to require, the measurements an engagement must report, the claims to distrust, and the cases where a traditional SEO agency is the better choice.
Deep dive
Generative Engine Optimization Agency: What Should You Actually Be Paying For?
A generative engine optimization agency can sell you monitoring, diagnosis, remediation, authority work, measurement or experimentation. Only some of those move the number. Here is how to tell which you are buying.
SEO for SaaS in the AI Search Era: What Traditional SEO Does Not Measure
Traditional SEO for SaaS still works. What changes in the AI search era is that buyers also get answers from ChatGPT, Perplexity and Google AI Overviews, and rank and traffic reports cannot see who those answers name.
Applied / adjacent
B2B SEO Agency vs AI Search Specialist: Which Problem Do You Actually Need Solved?
A B2B SEO agency and an AI search specialist solve different problems. This decision page tells you which one you have, when you need both, and when you should spend the money somewhere else first.
Originality Signals and Citation Patterns
AI engines deprioritize pages that look like everything else. The originality signals that move a post from the summary layer into the quote layer, and why recap content is the new thin content.
Search Console's Generative AI Report: 3 Things It Hides
Google's Generative AI report went live for every property on August 11, 2026. No queries, no clicks, no API access. Here is my own 19.7K-impression report.
How to Optimize Your Website for ChatGPT and Perplexity
Five steps to optimize a website for ChatGPT and Perplexity: allow GPTBot, ClaudeBot and PerplexityBot, add llms.txt and schema, write answer-first.
AI Citation Audit: What Predicted Citations Across 7 Sites
An AI citation audit of 7 websites, Ahrefs included: the 10 infrastructure checks, the 3 factors that predicted citations, and how to run yours free.
Why Domain Authority Is Irrelevant for AI Search (And What to Build Instead)
You're building backlinks for a metric that doesn't matter to ChatGPT or Perplexity. Data from 7 site audits answers the real question, does site authority matter in AI citation rankings, and shows what to build instead: a DA-92 site got cited 5% of the time, a DA-under-10 site got cited 15%.
llms.txt for AI Crawlers: Why robots.txt Is Not Enough
robots.txt was built for search engines, not AI crawlers. llms.txt gives LLMs structured context about your site that robots.txt can never provide.
Dev.to Cross-Posting Without SEO Damage: Canonical URLs and the 72-Hour Rule
Automate Dev.to cross-posting without SEO penalties. Configure Zapier delays plus canonical URLs in 10 minutes to protect your search rankings.
Content Intent Signaling: The robots.txt Directive That Controls How AI Uses Your Content
robots.txt controls access. Content Intent Signaling controls usage. Three new directives separate training from citation permission.
Bing Webmaster Tools AI Performance: 1,200 Copilot Citations Were Hiding There
The AI Performance tab in Bing Webmaster Tools showed ~1,200 Microsoft Copilot citations to my DR-25 site. Here is where the AI tab is and how to read it.
Entity-Level SEO vs Page-Level SEO: 8 AI Citations a Day After Switching
Bing AI cited my site 8 times a day after I stopped tuning individual pages. The principle: entity-level SEO is the floor; page-level work is the ceiling.
Cloudflare Will Block AI Crawlers by Default on September 15: What Site Owners Need to Do Now
Cloudflare blocks AI crawlers by default on September 15, 2026. Should you block, allow, or charge via Pay Per Crawl? Decision matrix + verification steps.
Chrome Prompt API: AI Visibility Scans at $0 Cost
Chrome 148 put the Prompt API and Gemini Nano in the browser. Here's what our citability.dev scan really costs, and which parts move client-side for $0.
Why ChatGPT Is Not Citing Your Website: I Measured 47 AI Answers
I asked ChatGPT, Claude, and Perplexity the 16 questions my buyers actually ask. My own site came up 3 times out of 47. Here is the method, the raw counts, and the gap I found.
Who Are the Experts on AI Search Visibility? Four Topics, Named Sources
Named practitioner sources for four AI search visibility topics, built from an 80-run citation panel across ChatGPT, Perplexity, Claude, and Gemini.
Why Isn't ChatGPT Citing Your Website? I Tested 5 Axes on a DR 25 Site and Got 1,500 Citations
1,500 AI citations on a DR 25 site in 90 days. The 5 checks (schema, llms.txt, OpenGraph, semantic HTML, robots.txt) that decide whether ChatGPT cites you.
I Ran My Own Analysis Past a Second Model Five Times. I Retracted Twice.
A working method for adversarial review between two AI models on your own data, what it cost in retractions, and the cheap instrument that settled it.
I Asked 3 AI Engines the Same 16 Buying Questions. They Agreed Under a Third of the Time.
A 47-answer study of who ChatGPT, Claude, and Perplexity recommend in one B2B category: six brands hold 89% of mentions, the engines overlap by about 30%.
How to Get Cited by ChatGPT: My 0/5 GEO Audit
I ran my own site through 5 buyer-intent queries on Perplexity and got cited zero times. Here is what GEO actually is and the pattern the winners share.
Perplexity Named Zero Brands, 40 Answers in a Row. Your Category Is Not the Reason.
480 answers across ChatGPT, Claude and Perplexity, in a two-year-old category and a twenty-year-old one. Which engine goes quiet is a property of the engine.
ClaudeBot: what it crawls and how to allow or block it
ClaudeBot is Anthropic's training crawler. Learn how it differs from Claude-User and Claude-SearchBot, and the robots.txt files to allow or block it.
Related tools and products
Audit your citability
Run the citability.dev scorer on any page to see what AI engines actually extract, cite, and miss.