How AI Is Changing SEO in 2026, and What We Actually Know

Most writing about AI and SEO, including an earlier version of this post, states things with a confidence nobody has earned. Search engines and AI vendors publish very little about how their systems choose sources. What follows separates the small number of things we can verify, the one thing we measured ourselves, and the large number of things we do not know.

What is actually different

Google shows AI-generated summaries above the results for many queries. Assistants like ChatGPT, Perplexity, and Copilot answer questions directly, and some of them cite sources and link out. That is real, and it is visible to anyone.

What follows from it is less clear than the industry pretends. A summary that answers the question can reduce clicks for that query. It can also send a click that would never have happened. We have seen confident percentages for the size of that effect, and we have not seen a methodology behind them that we would defend in public, so we are not going to repeat them.

"The ChatGPT crawler" is not one thing

This matters because people make rendering and robots.txt decisions based on a single imagined bot.

OpenAI documents several distinct user agents with different jobs. GPTBot collects data for model training. OAI-SearchBot builds the index behind ChatGPT search. ChatGPT-User fetches a page because a user, in a live conversation, asked about it. Other vendors run their own separate agents on the same pattern.

Blocking one does not block the others. Those agents differ in how they handle JavaScript, and the honest position is that this varies by crawler and changes without announcement. Anyone who tells you flatly that AI crawlers do not run JavaScript is describing some of them, not all of them, and probably not this month.

llms.txt is a proposal, not a protocol

llms.txt is a proposed convention: a markdown file at the root of your domain describing your site for language models. It has a spec and it has advocates. It does not have adoption commitments from the major AI vendors.

So, plainly: not having llms.txt does not make your business invisible to ChatGPT. Adding llms.txt does not put you into AI answers. Anyone selling either claim is selling you a file that takes ten minutes to write.

We publish one on this domain. It costs almost nothing, it might matter later, and we have no evidence it has done anything for us so far. That is the entire honest case for it.

The one thing we measured

Assistants that read the live web still have to get your content out of an HTTP response. If the content only appears after JavaScript runs, a crawler that does not render sees a page with nothing in it.

We ran 405 business websites through our crawler and got 368 analyzable results. We compared the rendered DOM to the raw HTML the server returned. In 92 of those 368 sites, at least one answer-critical element was present after rendering and absent from the raw HTML. Body text was missing in 57 cases, links in 51, and name, address, or phone details in 54.

Those sites were not selected at random, so this is not a probability that applies to your site. It is a defect we found often enough that checking for it is worth ten minutes of your time. View the page source, not the DOM inspector, and search it for a sentence you can see on the screen. If the sentence is not in the source, your content depends on the crawler choosing to render, and not all of them do.

By platform, the counts were: WordPress 37 of 139, Other or custom builds 34 of 107, Squarespace 13 of 46, GoDaddy 4 of 20, Wix 1 of 35, Webflow 1 of 15. One affected site out of 35 is not a platform verdict, so we are not going to declare a winner or a loser here.

Where AI answers actually come from

An assistant answering a question about a local business is not reading only your website. Depending on the system and the question, it may be drawing on a search index, map listings, review platforms, business directories, press coverage, and its own training data. Some of that data is years old. Some of it is other people's descriptions of you.

The practical consequence is that your website is one input among several, and the ones you do not control can contradict it. If your address is wrong in three directories, no amount of schema on your homepage settles the argument.

What we do not know

We do not know how any assistant weights its sources. We do not know whether structured data influences AI citation, though we add it anyway because it has separate, documented uses in search. We do not know how often the AI systems recrawl. We cannot show you that any change we have made to a site caused it to appear in an AI answer, and we have not seen anyone else demonstrate that causal link either.

Anybody offering you an "AI SEO" service with a guaranteed mechanism is describing a system they have not been shown.

What is worth doing anyway

The useful list is short, and every item on it was already worth doing before AI answers existed.

Put your content in the HTML. If a crawler has to run your JavaScript to learn what you sell, you are depending on a step that some crawlers skip.

Make the factual claims about your business easy to extract and identical everywhere. Name, address, phone, hours, services, service area. Same on your site, your Google Business Profile, and every directory that lists you.

Answer real questions in plain language on pages that exist for that purpose. Systems that summarize text reward text that is already clear.

Be present in the sources these systems read. Reviews, directories, and press are not website work, and they are where a large share of the material about you actually lives.

Keep your own measurement. Search Console still tells you what Google does with your pages. Nothing equivalent exists for assistants yet, so treat any dashboard claiming to measure your "AI visibility" as an estimate, including ours.

The honest status

We have measured one specific, real AI-visibility failure and we have written about it. On the rest of it we are working from the same public statements and the same guesswork as everyone else, and we will keep saying so until somebody publishes something better. When we can show that a change we made caused an AI system to cite a client, we will publish that too, along with the method.