Definition

llms.txt

llms.txt is a markdown file placed at a site's root that summarises what the site is and lists its most important pages, intended to help AI systems understand and cite it correctly.

It is a convention proposed by the community rather than a standard adopted by the major engines, and support is inconsistent.

Our own controlled testing found no measurable citation effect from adding one. Publish it as cheap insurance, not as a tactic with an expected return.

Nostimates measures llms.txt across twelve AI answer surfaces. Request access →

All terms

AEO (Answer Engine Optimisation)GEO (Generative Engine Optimisation)AI Overviews AI Mode Citation share n-sampling Query fan-out Grounding Share of voice (AI)Extraction success rate Surface Answer engine Citation Brand mention Mention rate Confidence interval Statistical significance Citation volatility Non-determinism Reproducibility Identity-free collection Personalisation Locale Residential proxy Bot detection Collection cost Credit Evidence retention Audit trail Parser version Canary prompt Data freshness Cadence Prompt set Head term Long-tail query Competitive set robots.txt AI crawler Training crawler Retrieval-augmented generation (RAG)Hallucination Answer box Featured snippet Zero-click search Entity Entity salience Knowledge graph Structured data JSON-LD schema.org FAQ schema Answer-first content Chunk Embedding Semantic search Prompt injection Market coverage Sentiment analysis Position tracking White-label data