Validate llms.txt files for AI agent discoverability. Built by Citability — the AI visibility scoring platform.
llms.txt is a proposed standard (llmstxt.org) for providing LLMs and AI agents with structured context about a website. It helps tools like ChatGPT, Claude, Perplexity, and Gemini better understand and cite your content.
This validator checks your llms.txt file against the spec, scoring it from 0–100 and flagging errors and recommended improvements.
pip install llms-txt-validator# Validate a remote site (fetches /llms.txt automatically)
llms-txt-validate example.com
# Validate a specific URL
llms-txt-validate https://example.com/llms.txt
# Validate a local file
llms-txt-validate ./llms.txtfrom llms_txt_validator import validate_llms_txt, fetch_and_validate
# Validate string content
result = validate_llms_txt(open("llms.txt").read())
print(f"Score: {result.score}/100")
print(f"Valid: {result.valid}")
print(f"Sections: {result.sections}")
# Fetch and validate from URL
result = fetch_and_validate("citability.ai")- H1 title (required) — 30 points
- Summary blockquote (recommended) — 20 points
- H2 section headers — up to 30 points
- Markdown links — up to 20 points
- URL format (absolute URLs) — warnings on relative URLs
For a comprehensive AI visibility scan that checks llms.txt and robots.txt AI rules, Schema.org, MCP endpoints, citation readiness, and 51 other AI discovery signals, try the free scanner at:
Citability scores domains across 5 pillars (Authority, Performance, Content, Social, Agentic) using 44+ metrics from Common Crawl, DataForSEO, PageSpeed Insights, and proprietary AI visibility scanners.
MIT — see LICENSE for details.
- llmstxt.org — the llms.txt spec
- Citability — full AI visibility scanning platform
- Citability Scanner — free domain scanner