What is llms.txt?

Definition

llms.txt is a proposed standard for a machine-readable text file at the root of your website (at example.com/llms.txt) that points large-language-model tools to your site's most important content. It sits alongside robots.txt and sitemap.xml: robots.txt tells crawlers what they can access, sitemap.xml lists every URL, and llms.txt curates the URLs and context you consider most important.

The file uses a simple Markdown-based format. It typically starts with a project name and short description, then organizes links to key pages by category (documentation, tutorials, product pages, blog posts). Tools that read llms.txt can use these curated links as a starting point.

Why It Matters

Be clear about what it does and doesn't do. As of 2026, none of the major AI search engines (Google, ChatGPT, Claude, Perplexity) has confirmed that it reads llms.txt when choosing which pages to cite, so it is not a ranking or citation lever — and SEObolt's GEO Score gives it no weight. It is still useful for AI coding assistants and agents that do read it, which is why many developer-documentation sites publish one.

The adoption trajectory matters too. llms.txt was proposed by Jeremy Howard (co-founder of Answer.AI and fast.ai) and has picked up meaningful adoption among AI-focused sites since. Publishing one is cheap and harmless; just don't expect it to change how often AI answers cite you.

How It Works

A minimal llms.txt file looks like this:

# SEObolt

> SEObolt is an SEO platform that tracks AI search visibility across ChatGPT, Claude, Perplexity, Gemini, and DeepSeek alongside traditional Google Search Console analytics.

## Documentation
- [Features overview](https://seobolt.io/#features)
- [Pricing](https://seobolt.io/pricing)

## Learn
- [What is GEO?](https://seobolt.io/glossary/generative-engine-optimization)
- [What is llms.txt?](https://seobolt.io/glossary/llms-txt)

The file starts with an H1 site name, a blockquote description, and category headers with markdown links. Optional llms-full.txt versions can also include the full text of key pages so AI crawlers do not need to fetch each URL separately.

SEObolt's GEO Score checks for llms.txt presence as one of the Technical Accessibility factors and flags missing files as a fixable optimization.

Related

• Generative Engine Optimization (GEO) — the broader practice that llms.txt fits into
• Google AI Overviews — one of the highest-volume AI citation surfaces
• Schema markup — the structured-data companion to llms.txt
• GEO Score (SEObolt feature) — audits llms.txt presence and configuration

Frequently Asked Questions

Is llms.txt an official standard?

llms.txt is a proposed community standard rather than a formal specification from a standards body. It has been adopted by a growing number of AI-focused sites and is supported (or planned) by several major AI crawlers including those from Anthropic and Perplexity. Adoption is real but still evolving.

Where does llms.txt go on my site?

The file lives at the root of your domain: example.com/llms.txt. Some implementations also support llms-full.txt for a larger version that includes the full text of key pages, published alongside the standard llms.txt.

Does llms.txt replace robots.txt or sitemap.xml?

No. robots.txt controls what crawlers can access, sitemap.xml lists every URL, and llms.txt curates the most important URLs for AI understanding. The three files serve different purposes and coexist. Most well-configured sites will have all three.