AI Visibility: how to check if your website is cited by ChatGPT, Gemini and Perplexity in 2026

In 2026, over 60% of internet searches end without a single click to a website. Users get their answers directly from ChatGPT, Gemini, Perplexity or Claude. If your website isn't cited by these AIs, you're losing potential customers without even knowing it.

Traffic from AI engines shows a 14.2% conversion rate, compared to just 2.8% for Google Search. When an AI cites your site, the user who clicks already has a very strong purchase intent. That's 5 times more effective than classic SEO.

What is AI visibility?

AI visibility measures how often and how well your brand, website or products are mentioned in responses generated by large language models (LLMs) like ChatGPT, Gemini, Perplexity and Claude.

Unlike classic SEO which optimizes your ranking in Google search results, AI visibility concerns your presence inside AI-generated responses themselves. The user no longer sees a list of links — they see a synthesized answer. And if you're not in that answer, you don't exist.

Why are 78% of websites invisible to AI?

The main reason is technical: most websites block AI crawlers in their robots.txt file without knowing it. GPTBot (ChatGPT), ClaudeBot (Anthropic) and PerplexityBot are often blocked by default by hosting providers or security plugins.

Other common causes include: no llms.txt file (a new standard that describes your site to AIs), lack of Schema.org structured data, and content not structured for citation (no FAQ, no direct answers, no short factual paragraphs).

How to check if your website is visible on ChatGPT?

The manual method involves asking 5 typical customer questions in ChatGPT, Gemini and Perplexity, then checking if your site appears in the responses. For example, if you're a plumber in London, ask: "What's the best plumber in London?" and see if your business is cited.

The problem with this approach: LLMs are non-deterministic. Results change based on time, location and wording. An automated tool like RadarLLM.ai asks 10 questions 3 times to 4 AI engines (120 tests) and provides a reliable score, answer excerpts and the competitors recommended instead of you.

What is AEO (Answer Engine Optimization)?

AEO is the practice of structuring your content so it gets selected as a direct answer by AI engines. This includes: using questions in your H2/H3 headings, writing short answers (30-50 words) at the beginning of paragraphs, implementing FAQPage schema in JSON-LD, and citing reliable sources.

What is GEO (Generative Engine Optimization)?

GEO goes further than AEO. It aims to maximize your overall presence in generative responses. This involves: creating an llms.txt file, allowing all AI bots in robots.txt, structuring content in short thematic blocks, and strengthening your EEAT signals (Expertise, Experience, Authority, Trust).

What is the llms.txt file and why does it matter?

The llms.txt file is an emerging standard (similar to robots.txt) that describes your website to AI models. It lists your main pages, business activity, and contact information. It's a strong GEO signal that helps AIs understand your site and cite you correctly.

RadarLLM automatically generates a custom llms.txt file for your site, ready to upload to your domain root.

The 5 priority actions to improve your AI visibility

What's the difference between SEO, AEO and GEO?