llms.txt generator & validator
llms.txt is optional, and a site works fine without one. If you want one, this free llms.txt generator drafts it from your sitemap, with your site name, a summary and your pages grouped by section. As an llms.txt validator, it checks your live file: the heading, the format, and whether its links still load.
This tool checks once. Site Health Monitoring keeps checking.
It checks on a schedule and alerts you when the result changes. Ask Theo, the AI assistant in the app, to explain any finding.
The same check on every page you visit
In the free VitalSentinel SEO Extension for Chrome, one click shows whether the site has an llms.txt, as one of 10 AI readiness checks, for the page you have open.
- Free
- No account needed
- One click
What it checks
- Reads /llms.txt and /llms-full.txt and rates each Present, Not present or Has errors, by the same rules as Site Health Monitoring
- Checks the on-site links among the first 25 in each file. A 404, a 410 or a noindex page counts as dead
- Compares the file with the llmstxt.org layout: an H1, a short summary, then H2 sections of links
- Generates a draft from your sitemap: your homepage plus up to 25 pages, spread across your sections, each with its title and description
What it does not
- llms.txt is a proposal, not a standard. Google says its search does not need AI text files, and no AI company has said its crawlers read the file for training or ranking
- It checks only absolute links on your own host, and only among the first 25 in each file. A redirecting link is not counted either way
- The draft is a starting point. It reads at most 25 pages, so a large site needs editing before you publish it
- It reads the file at the root of your site only, not one at a deeper path such as /docs/llms.txt
Questions
What is llms.txt?
A markdown file at /llms.txt that gives AI tools a short map of your site: its name, a one-line summary, and links to the pages worth reading, grouped under headings. Jeremy Howard proposed it in 2024, and llmstxt.org describes the format.
Do AI crawlers read llms.txt?
Not in any way the big AI companies have committed to. Google's guidance for AI features in Search says you do not need new machine-readable files or AI text files. Coding agents and AI assistants do fetch llms.txt on demand, mostly for developer documentation, which is where the file is most useful today.
What makes an llms.txt valid?
This tool uses the same rule as Site Health Monitoring. The file answers 200, is not empty, is not served as an HTML page, and its first line is an H1 heading such as "# Example". Its links count as broken when at least two, and a fifth or more, of the ones checked are dead.
Should I also publish llms-full.txt?
Only if you want agents to have your full content in one file. llms-full.txt is not part of the llmstxt.org format, but many documentation platforms publish one next to llms.txt with the text of every page. llms.txt stays short and links out.
More free tools
Fair use, and how to recognize us
5 per minute · 25 per hour · 100 per day per IP (per /64 for IPv6), plus a per-site limit
Every request these tools make sends this user agent, including the ones that load a page in a real browser. What a run records is set out in our privacy policy.
Mozilla/5.0 (compatible; VitalSentinel Free Tools Bot/1.0; +https://www.vitalsentinel.com/bot)
Stop checking by hand
Core Web Vitals from real users, indexing and robots.txt, uptime and SSL, monitored continuously. Start on the Free plan and add your first domain in under a minute.