llms.txt Explained
llms.txt is a plain Markdown file placed at a website's root that gives AI systems a curated index of a site's most important pages and what each one covers — similar in purpose to sitemap.xml, but written for language models rather than search crawlers.
What is llms.txt?
llms.txt is a lightweight, Markdown-formatted text file placed at a domain's root (https://example.com/llms.txt) that lists a site's highest-priority pages with a short description of each, so AI systems can quickly understand what a site covers without having to crawl and infer it.
How is it different from sitemap.xml?
Sitemap.xml is an exhaustive, machine-formatted (XML) list of every indexable URL, meant for traditional search crawlers. llms.txt is a curated, human-readable Markdown file meant for large language models — it doesn't need to list every page, just the ones that best represent the site's authority areas.
What does the format look like?
A valid llms.txt file starts with an H1 title and optional summary blockquote, followed by H2-grouped sections, with each entry formatted exactly as:
- [Title](URL): Description
Does llms.txt guarantee citation?
No — like robots.txt, llms.txt expresses intent and is only useful if an AI system's crawler chooses to read and honor it. It's not yet universally adopted, but early adopters gain a structural advantage as more AI systems begin using it for retrieval. Tyfig maintains an up-to-date llms.txt for this exact reason.