Tools
Free llms.txt Checker and Validator
Paste a URL to see whether it publishes an llms.txt file, and whether it has real section structure and enough content to be useful to an AI agent.
Worked example: checking this site
Enter https://www.visiscan.app. The checker requests /llms.txt, confirms it is readable text, and checks for a site summary, section headings, and canonical page links. Use the returned gaps as an editing checklist, then run the same URL again after publishing.
What should llms.txt contain?
A useful llms.txt gives machines a short, factual map of the site: what the organization does, who it serves, and canonical links to pricing, methodology, documentation, policies, and important resources. It should point to maintained pages instead of duplicating long marketing copy.
What llms.txt does not do
Publishing the file does not guarantee ranking or citation. Google does not require an AI-specific file for AI Overviews or AI Mode; ordinary crawlability, helpful content, and Search fundamentals still apply. Treat llms.txt as an optional discovery aid for agents that choose to read it.
After a change, fetch /llms.txt directly, confirm it returns plain text, remove unsupported claims, and keep prices and product limits synchronized with the visible site.
How llms.txt connects to your visibility score
VisiScan's full report checks whether your site publishes an llms.txt file and grades it for completeness. A well-structured file that maps agents to your key pages (about, pricing, documentation, methodology) improves your Readiness score. The checker above tells you whether your file exists and has substantive content — fix it before running a full scan. For the broader picture of machine-readable discovery and getting cited, see how to get your business cited by ChatGPT.
Questions about llms.txt
- What does the llms.txt checker test?
- It fetches /llms.txt from the site you enter and reports whether the file exists, returns plain text, has real section structure, and carries enough content to be useful to an agent rather than being an empty stub.
- How much does the llms.txt checker cost?
- Nothing. It is free, needs no signup, and can be run against any public site.
- Which AI engines read llms.txt?
- No major engine has committed to reading it. llms.txt is a proposed convention, and Google has said no AI-specific file is required for AI Overviews or AI Mode. Treat it as an optional discovery aid for agents that choose to read it, not as a ranking input.
- What is the difference between llms.txt and robots.txt?
- robots.txt controls crawler access — which agents may fetch which paths. llms.txt does not grant or deny anything; it is a content map that describes the site and links to its important pages. A site needs correct robots.txt rules regardless of whether it publishes llms.txt.
- What are the checker's limits?
- It grades structure and substance, not truthfulness. It cannot tell whether the prices, claims, and links inside your file are still accurate — that is on you to keep synchronized with the visible site.
- How do I create an llms.txt file?
- Use the llms.txt generator, which reads your live pages and builds the file from what is actually on the site, then fill in anything it reports as a gap and publish the result at the root of your domain.