What is an AI visibility checker?

An AI visibility checker is a tool that tests whether AI assistants can reach, read and quote your website. It looks at the things that decide this: whether you block AI crawlers, whether your pages work without JavaScript, whether your facts are machine-readable, and whether your writing can be quoted in one clean passage. Traditional SEO tools do not check most of that.

What AI visibility actually means

People increasingly ask an assistant instead of typing a search. They ask ChatGPT for a recommendation, or Perplexity for a comparison, or they read the AI summary at the top of Google and never scroll. In each case something has to pick which sources to trust and cite.

AI visibility is whether your site is available to be that source. It is not a ranking position. There is no reliable number to report, because the same question asked twice can produce different citations. What you can measure is the set of conditions that have to be true before you are eligible at all.

What an AI visibility checker looks at

Whether you block AI crawlers

This is the first and bluntest check. AI companies crawl the web with named user agents, and your robots.txt file can allow or refuse each one. The common names are GPTBot and OAI-SearchBot from OpenAI, ClaudeBot from Anthropic, PerplexityBot, and Google-Extended, which controls whether Google may use your content for Gemini and AI Overviews.

Plenty of sites block these without ever deciding to. A security plugin adds a rule, a template ships with a blanket deny, or someone copies a robots.txt from a site that made a deliberate choice you did not. Our checker reads your robots.txt and reports which of these agents you allow and which you refuse, so the decision becomes a decision.

Whether your content survives without JavaScript

Google renders JavaScript. Most AI crawlers do not, or do it inconsistently. If your main content is injected by a client-side framework after page load, a crawler that only reads the initial HTML sees an empty shell.

This is the failure that surprises people most, because the page looks perfect in a browser. The fix is server-side rendering or static generation for anything you want quoted.

Whether your facts are machine-readable

Structured data is how you state facts instead of implying them. Schema markup lets you say plainly what your organization is called, what a product costs, who wrote an article and when. A parser reading prose has to guess at all of that.

A visibility checker looks for the schema types that match your page and flags where they are missing or malformed. It is the same markup that drives rich results in normal search, which makes it one of the few jobs that pays twice.

Whether your answers are quotable

An assistant citing you needs to lift a passage that makes sense on its own. A paragraph that opens with “as mentioned above” cannot be quoted without the paragraph before it, so it usually is not quoted at all.

The habit that helps is simple. Ask a question in a heading, then answer it completely in the first two sentences underneath. Add the detail after that, for the humans who keep reading.

Where llms.txt fits, honestly

You will see llms.txt described as essential. It is a proposed standard: a Markdown file at the root of your site that lists your important pages in a form a language model can read cheaply.

Here is the honest position. It is a proposal, not a specification anyone is obliged to follow. Google has said publicly that Search does not use it, and no major AI provider has committed to reading it. It costs almost nothing to publish, it is a tidy summary of your own site, and it may matter later. Treat it as cheap insurance, not as the thing standing between you and being cited.

Our own checker reports whether the file exists and whether it is well-formed. It does not tell you that a missing llms.txt is why nobody quotes you, because that would not be true. If you want the format and how to write one, the full guide to what llms.txt is covers it.

What no AI visibility checker can tell you

No tool can tell you how often ChatGPT mentions your brand. Assistants do not publish that, results vary between users and sessions, and any product claiming a precise share-of-voice number is sampling a handful of prompts and calling it data.

A checker measures readiness, not outcomes. It answers “is there anything on my side stopping this?” — which is the part you control.

How to run one on your site

Paste your URL into the free website checker on the homepage. The scan takes about thirty seconds and covers AI crawler access, structured data, rendering and page speed together, because they are not separate problems. No signup, no card.

If you want the specifics of what to change afterwards, the generative engine optimization checklist walks through the fixes in priority order. If your site is not appearing in ordinary search either, start with why your website is not showing up on Google instead — being indexed normally is the foundation the rest of this sits on.