Quick answer: llms.txt is a proposed Markdown file placed at the root of a website (/llms.txt) that gives large language models a short summary of the site and links to its most useful content. Google states that Google Search does not use llms.txt for rankings or AI Overviews, and no major AI company has confirmed relying on it. It is cheap to add and harmless, but it should be a low priority next to crawlable, high-quality content.
Few SEO topics have generated as much noise relative to their impact as llms.txt. Plugins add it with one click, agencies sell it as an “AI ranking file,” and site owners ask me whether they are missing out. Here is what the file actually is, what the evidence says and when it is worth adding.
What llms.txt is
The format was proposed in September 2024 by Jeremy Howard of Answer.AI. The idea: websites are built for humans, with navigation, scripts and ads, and they are awkward for language models to read within limited context windows. A Markdown file at a known location could give models a clean overview.
A basic file looks like this:
# Example Plumbing Co.
> Licensed plumbing company serving Mesa and Chandler, Arizona since 2009.
## Services
- [Water heater repair](https://example.com/water-heater-repair/): repair and replacement of tank and tankless units
- [Drain cleaning](https://example.com/drain-cleaning/): hydro jetting and camera inspection
## Guides
- [Water heater replacement cost](https://example.com/water-heater-cost/)Some sites also publish llms-full.txt, which includes the full text of key pages in one file.
Is llms.txt the same as robots.txt?
No. robots.txt tells crawlers what they may access. llms.txt only suggests what is worth reading. It cannot block or allow anything. If you want to control AI crawlers, that is done in robots.txt, as covered in my robots.txt guide.
What Google says
Google’s guide to generative AI features in Search states that you do not need new machine-readable files, AI text files or special markup to appear in AI features, and that Google Search does not use them. Google representatives have also compared llms.txt to the old keywords meta tag: something site owners can declare but search engines do not need.
There is one nuance. Lighthouse, Google’s open-source auditing tool, added an “agentic browsing” category in 2026 that includes a check for llms.txt. That audit is about how well a site works for AI agents browsing on a user’s behalf, not about Search rankings, and a missing file is not marked as a failure.
What about ChatGPT, Claude and Perplexity?
At the time of writing, no major AI provider has publicly confirmed that its crawlers or answer systems rely on llms.txt for selecting or citing sources. Server log studies published by SEO practitioners have generally found few requests for the file from AI crawlers. Developer tools and coding assistants are the clearest current use case, especially for documentation sites.
Should you add llms.txt?
| Site type | Recommendation |
|---|---|
| Software or API documentation | Worth adding; developers and coding tools do use it |
| Large content or e-commerce sites | Optional; low effort if your CMS generates it |
| Local service businesses | Low priority; focus on your Business Profile, pages and reviews first |
If you add one, keep it accurate, short and in sync with your site. Do not stuff it with keywords or claims that are not on your pages; there is no benefit, and it misrepresents your business to any system that reads it.
What actually improves AI visibility
- Pages that are crawlable, indexed and eligible for snippets.
- Clear, direct answers backed by unique expertise and facts.
- A consistent business identity across your site and the web, covered in my guide to entity SEO.
- Mentions in the sources AI tools draw on, such as reviews, directories, news and comparisons.
The full approach is in my guide to generative engine optimization. If you want help prioritizing AI visibility work that actually moves results, see my AEO and GEO service.
Frequently asked questions
Does llms.txt improve Google rankings?
No. Google states that Google Search does not use it.
Can llms.txt hurt my SEO?
Not if it is accurate. Google says such files will not help or harm your Search visibility.
Where does llms.txt go?
At the root of your domain, such as https://www.example.com/llms.txt, served as plain text or Markdown.
Do WordPress SEO plugins create llms.txt?
Several popular plugins can generate one automatically. Review the output, because automatic files often list pages you would not choose.
Sources: llmstxt.org: The /llms.txt file proposal; Google Search Central: Guide to optimizing for generative AI features; Chrome for Developers: Lighthouse.
