Free tool
Paste your file or enter a domain. We check it against the llms.txt spec — title, summary, sections, and links — and tell you exactly what to fix.
We look for /llms.txt at the domain root.
An llms.txt file is a markdown file at your site root that points language models to your most important pages. A valid file has one H1 title, a blockquote summary, optional detail prose, then H2 sections containing curated [name](url) link lists. This validator flags missing or duplicate titles, a missing summary, empty sections, malformed link URLs, and headings deeper than H2 — and scores the result out of 100.
llms.txt is the concise index — a curated map of links. llms-full.txt is the optional, larger companion that inlines the actual content so a model has everything in one fetch. Keep the index short and move bulk content into the full file. For the full breakdown, read llms.txt explained.
A clean llms.txt is one signal. Getting ChatGPT, Perplexity, and Google AI Overviews to cite you is the work — answer-first content, schema, and entity coverage. That's our generative engine optimization practice.
