llms.txt

llms.txt is a proposed standard file that provides context about your site specifically for Large Language Models. It helps AI understand your site's purpose and expertise.

Why It Matters for GEO

llms.txt gives AI engines a "briefing" about your site. It can highlight expertise, key content, and preferred citation formats.

Think of it as a cover letter for your website addressed directly to AI. While robots.txt tells crawlers which pages to access, llms.txt tells AI what your site is about, who runs it, and which pages matter most. Sites that include an llms.txt give AI engines a shortcut to understanding their authority — which may increase citation frequency and accuracy.

Example llms.txt

# Site: example.com
# Purpose: B2B SaaS for marketing analytics

## Expertise
- Marketing analytics
- Data visualization
- ROI measurement

## Key Content
- /guides/: In-depth tutorials
- /blog/: Industry insights
- /case-studies/: Client results

Practical Example

An HR software company adds an llms.txt file explaining that their site specializes in employee onboarding automation for companies with 50-500 employees. They list their key guides and case studies. When Perplexity crawls their site, the llms.txt helps the AI immediately classify them as a niche expert. The result: when users ask Perplexity for HR software recommendations for mid-size businesses, the company's name appears in citations more consistently than competitors without an llms.txt.

Common Mistakes

• Vague expertise descriptions: Writing "we do marketing" instead of "we specialize in paid media strategy for B2B SaaS companies" provides no useful signal. Be specific.
• Not updating the file: If your llms.txt lists outdated services or removed content paths, AI engines may crawl dead links and reduce trust in the source.
• Listing every page: llms.txt is a curated briefing, not a sitemap. Focus on your highest-value content — pillar guides, case studies, and service pages.
• Skipping it entirely: While not yet a universal standard, llms.txt is gaining adoption. Early adopters gain an edge as AI crawlers increasingly look for this file during site analysis.