llms.txt Generator and Checker
Check whether a site's llms.txt follows the llmstxt.org spec, with a plain-English fix for every problem. No file yet? Generate a draft from your sitemap and page titles in about twenty seconds.
Fetches /llms.txt and /llms-full.txt, validates the format against the llmstxt.org spec and tests up to 25 of the links.
What is llms.txt?
llms.txt is a markdown file at yourdomain.com/llms.txt that tells AI models what your site is and which pages matter. It works like a table of contents written for a machine: one title, a one-line summary, then short lists of links with a note on each. Jeremy Howard of Answer.AI proposed it in September 2024, and the format lives at llmstxt.org. You can see a working example in our own llms.txt.
Does llms.txt help with ChatGPT, Perplexity or Google?
Honestly, not in any way anyone has confirmed. It is a proposed standard, not an adopted one. OpenAI, Perplexity and Google have not said their answer engines read llms.txt when choosing what to cite, and Google has said its search systems do not use it. Where the file is used today is by coding assistants and AI agents that go looking for it when pointed at a site or its documentation. When we checked 221 Tampa Bay business websites, the businesses AI engines recommended had an llms.txt at the same rate as the ones they did not: 37%.
So publish one because it is cheap, harmless and forces you to decide which pages define your business, not because it will move rankings. What actually gets a business named in AI answers is covered in our guide to answer engine optimization. To see whether ChatGPT, Perplexity and Google AI Mode name you today, track it with Cited.
The llms.txt format
The spec is short. In order: one # H1 with the site or project name (the only required part), an optional > blockquote summary, optional paragraphs with no headings, then ## H2 sections that contain only list items in the form - [Title](url): note. A section named ## Optional marks links a model can skip when it is short on context.
# Acme Plumbing > Acme Plumbing is a licensed plumber in Tampa, FL, offering > 24/7 emergency repairs, water heaters and repiping. Service area: Tampa, St. Petersburg and Clearwater. ## Services - [Emergency plumbing](https://acme.com/emergency): 24/7, 60-minute arrival - [Water heaters](https://acme.com/water-heaters): repair and install ## Company - [Pricing](https://acme.com/pricing): flat-rate price list - [Contact](https://acme.com/contact): phone, hours, booking ## Optional - [Blog](https://acme.com/blog)
Common llms.txt mistakes
- The URL returns HTML. Many sites answer every unknown path with their homepage or a styled 404, so /llms.txt looks live but is not a text file.
- Paragraphs inside sections. Under an H2, the spec expects link lists only. Put prose above the first H2.
- Bare or relative URLs. Write
[Pricing](https://example.com/pricing), not a naked link or/pricing. - H3 headings and nested structure. The format uses only H1 and H2.
- Dead links. Pages get renamed and the file never gets updated. Re-check it after every site change.
Want to know where AI could save your team time beyond a text file? Take the free AI readiness audit. It is nine questions and gives you a score straight away.