Explainer

What is an LLM SEO checker — and do you need one?

By Zeb Choudhry · Visus · 4 July 2026 · 6 min read

An LLM SEO checker (also called an AI visibility checker or GEO audit tool) tests whether your website has the right signals for large language models — ChatGPT, Perplexity, Google AI Overviews — to cite and recommend your business. It checks AI-specific signals that traditional SEO tools don't measure: AI crawler access, entity clarity, answer-ready content, and llms.txt compliance. Most businesses need one if buyers in their category are using AI to find services. Try the free Visus LLM SEO checker.

What an LLM SEO checker actually tests

LLM SEO — also called GEO (Generative Engine Optimisation) — is about making your business discoverable and citable by AI answer engines. An LLM SEO checker evaluates the signals that determine citation likelihood:

A good LLM SEO checker scores each of these signals and returns a prioritised list of what to fix first — not a generic audit, but a ranked list based on what has the most impact on citation likelihood.

How it's different from traditional SEO tools

Traditional SEO tools (Semrush, Ahrefs, Screaming Frog) are excellent at what they do: keyword rankings, backlink analysis, technical crawl health. But they don't check LLM SEO signals:

An LLM SEO checker fills this gap. It doesn't replace your traditional SEO tool — it complements it.

What a score of 58 means

In our benchmark of 60 UK businesses, the average AI visibility score was 58 out of 100. Scores below 40 indicate AI systems struggle to identify the business. Scores above 80 are where citation likelihood becomes strong — Fozias restaurant reached 80 and became the #1 Perplexity result in their category.

Do you actually need one?

If your buyers use AI tools to find services like yours, yes. Here's how to know:

If you're unsure whether AI search matters in your category, do the manual check: go to ChatGPT and ask "best [your service] in [your location]". If a competitor appears, AI search is already driving buyers in your market.

Free vs paid LLM SEO checkers

The LLM SEO checker market is new. Options range from:

For most UK small businesses and agencies, the free check + Fix Pack covers everything you need to get started. The Visibility Monitor becomes valuable once you've applied fixes and want to track whether they're working.

How to use an LLM SEO checker effectively

  1. Run the audit — get your score and gap list
  2. Fix the highest-impact gaps first — AI crawler access and entity clarity are typically fastest with highest payoff
  3. Re-audit after 4 weeks — check whether your score has improved and new gaps have emerged
  4. Add monitoring — once your on-page signals are strong, track whether AI tools are actually recommending you in buyer queries

Try the free LLM SEO checker

Score out of 100. Top 3 gaps. Under 60 seconds, no credit card required.

Run free LLM SEO check