Not for AI search visibility. Google says its Search systems ignore the file. In Ahrefs' log data, 97% of llms.txt files received no requests at all in May 2026, and SE Ranking found no link between having the file and being cited by AI models.

The file does have a small audience. It is coding agents, not the bots that fetch pages for AI answers.

What llms.txt is

Jeremy Howard, co-founder of Answer.AI, proposed llms.txt in September 2024. It is a plain Markdown file at the root of a site, at yoursite.com/llms.txt, that summarises what the site is and links its most useful pages. The idea is that an AI agent can find its way around a site without crawling every page.

It is a proposal, not an agreed standard. The llmstxt.org page was last updated in August 2026, and Howard writes there that the files are used most heavily for software documentation, where coding agents follow them to technical references.

The file controls nothing. Blocking or allowing AI crawlers is still the job of your robots.txt file.

What Google says

Google's guide to optimising for generative AI features covers this in a section headed "Mythbusting". It says you don't need llms.txt or other AI text files to appear in Google Search or its AI Overviews and AI Mode, "as Google Search itself doesn't use them". Creating one "will neither harm nor help your site's visibility or rankings in Google Search".

Chrome's Lighthouse tool now checks for the file in its agentic browsing audits. Its documentation marks a missing file as not applicable, because "providing the file is optional at the moment". That check is about agents that browse a site for a user. It has nothing to do with Search rankings.

Who reads the file

Ahrefs ran the largest log study I found. It checked 137,210 domains that use its analytics tool and had traffic in May 2026. 28% published a valid llms.txt file, and Ahrefs treats that as an upper bound because its customers lean technical.

97% of those files received no requests of any kind in May.

The remaining 3%, about 1,100 domains, received around 22,000 requests between them. SEO audit tools sent 21.7% of those. AI agents such as Anthropic's Claude Code sent 10.5%. The bots that fetch pages for live AI answers, such as OpenAI's search bot and PerplexityBot, sent 1.1%. Slack's link-preview bot fetched llms.txt files more often than PerplexityBot did.

No AI bot asked for an llms.txt file on a site that didn't have one. Ahrefs' reading is that AI tools fetch the file only when a link, an index or an instruction tells them it exists.

Two limits apply. The sites are Ahrefs customers, not a random sample. And a request only shows the file was fetched, not that anything used it, so Ahrefs treats every figure as a ceiling.

Does having the file change citations?

SE Ranking analysed nearly 300,000 domains and found that 10.13% had an llms.txt file. It compared that with how often each domain was cited in AI answers. It used standard correlation tests and a machine-learning model, and found no link. When it removed llms.txt from the model, the model's predictions got more accurate.

SE Ranking does not say which AI platforms it sampled or over what period, and like Ahrefs it sells SEO tools. Its result is a correlation, so it cannot rule out a small effect it was unable to detect.

Where the file might matter

Coding agents are the main readers in Ahrefs' data. If your firm publishes developer documentation or an API, an llms.txt file gives those agents a map to the right pages, which is what the format was built for. Most B2B services firms publish neither.

There is one risk to manage. Ahrefs notes that agents are built to trust the file, and it found a research crawler studying llms.txt files as a route for prompt injection: hiding instructions for an AI inside content it reads. The llmstxt.org page lists Wix and the Yoast plugin for WordPress among the tools that generate the file automatically. If yours does, check what it says and who can edit it.

What I'd do

In my view, an llms.txt file is not worth paying for if the goal is AI citations. If your CMS already creates one, leave it in place and review it once. If an AEO proposal lists llms.txt as a deliverable, ask what evidence it has that the file changes citations.

The time is better spent on the checks that decide whether AI tools can use your site at all. The first is whether your robots.txt lets their crawlers in. We cover that in is your website blocking the AI bots you want to cite you.

A few common follow-up questions

Does Google use llms.txt?

No. Google's guide says Search ignores the file, and that creating one neither helps nor harms visibility in Search. That covers AI Overviews and AI Mode.

Does ChatGPT read llms.txt?

Rarely, in Ahrefs' data. OpenAI's GPTBot training crawler was the largest of the AI training crawlers at 4.51% of requests, and OpenAI's search bot was the largest retrieval bot at 0.74%. I found no statement from OpenAI that ChatGPT uses the file to choose its sources.

Is llms.txt the same as robots.txt?

No. robots.txt tells crawlers what they may access. llms.txt is a summary and a list of links, and it blocks nothing.