# LLMSRank guides > Plain-language guides to llms.txt, markdown versions of pages and AI-readiness, with the llms.txt Index research behind LLMSRank's rubric. This file covers /learn only; the site-wide index is https://llmsrank.dev/llms.txt. ## Hub - [llms.txt: tools and guidance](https://llmsrank.dev/learn.md): Check your site’s llms.txt for free, then read plain guides to the llms.txt proposal: the format, markdown page versions, and how it relates to robots.txt. ## Guides - [About llms.txt](https://llmsrank.dev/learn/llms-txt.md): What llms.txt is, why it exists, where the file lives, its exact format, how agents use it, who publishes it, and what it is not, per the llmstxt.org v2 text. - [Writing an llms.txt file](https://llmsrank.dev/learn/writing-llms-txt.md): How to write an llms.txt file step by step, with complete examples for a small business and a docs site, the proposal’s guidelines and the mistakes we see most. - [Markdown page versions and link relations](https://llmsrank.dev/learn/markdown-pages.md): The llms.txt convention for markdown versions of pages (page.html.md or page.md), and the rel="alternate" and rel="describedby" links agents use to find them. - [llms.txt, robots.txt and sitemap.xml](https://llmsrank.dev/learn/llms-txt-robots-txt-sitemap.md): How llms.txt differs from robots.txt and sitemap.xml: purpose, readers, location, format and control, and why the proposal says a sitemap is no substitute. - [Does ChatGPT, Claude, Perplexity or Google read llms.txt?](https://llmsrank.dev/learn/does-ai-read-llms-txt.md): What each AI vendor has documented about reading llms.txt, with dates: Google Search ignores it; OpenAI, Anthropic and Perplexity have published nothing either way. - [llms.txt vs AGENTS.md vs robots.txt](https://llmsrank.dev/learn/llms-txt-vs-agents-md.md): Three files, three readers: robots.txt sets crawler access, llms.txt maps your content for AI agents, AGENTS.md instructs coding agents. Compared, with sources. - [How to check your llms.txt](https://llmsrank.dev/learn/check-llms-txt.md): Check an llms.txt for free: scan it on LLMSRank, work through the manual checklist step by step, or let an agent check it, and know what no check can tell you. - [llms.txt generators: what generated files miss](https://llmsrank.dev/learn/llms-txt-generators.md): What llms.txt generators do well and what they leave to you: link descriptions, curation, scope and routing, measured against the llms.txt Index of real files. - [llms.txt release notes](https://llmsrank.dev/learn/release-notes.md): What changed in the llms.txt proposal, newest first: v2 (2026-08-10), the optional BOM (2026-06-09) and v1 (2024-09-03), plus LLMSRank’s own rubric releases. - [What we got wrong](https://llmsrank.dev/learn/what-we-got-wrong.md): A measurement product is only as good as its willingness to be wrong in public. Three times we published a number, found it was wrong, and said so — with the causes. - [The llms.txt year in review, 2026](https://llmsrank.dev/learn/llms-txt-2026.md): What changed for AI-readable websites in 2026, what our scan of 187 published llms.txt files found, and four things that move AI visibility we cannot measure. ## Research - [The llms.txt Index: how 187 sites score](https://llmsrank.dev/learn/research.md): Aggregate results from 187 real llms.txt files scored with LLMSRank rubric v2.1: grades, the checks most sites miss, and every audit's pass rate.