llms.txt
41 established claims - 11 refused by the grounding gate
Verdict
Google added a note to its AI optimization guide on June 15, 2026 clarifying Google Search's usage of llms.txt files, and as of July 10, 2026, Google Search Central states that Google Search ignores llms.txt files and that creating or maintaining them neither harms nor helps visibility or rankings in Google Search, while Chrome for Developers Lighthouse documentation instructs site owners to create an llms.txt file in the site root and describes the file as an optional emerging convention. Ahrefs log analysis reported on June 16, 2026 across 137,000 domains found 97% of llms.txt files received zero requests, only about 1,100 of roughly 38,000 valid files received any traffic, and SE Ranking's analysis of 300,000 domains showed no connection between having an llms.txt file and AI citation frequency. On August 7, 2026, Search Engine Journal published a statement attributed to Google's John Mueller saying no AI system currently uses llms.txt and that server logs make this obvious. As of August 10, 2026, llmstxt.org states llms.txt is used most heavily for software documentation, where coding agents follow the files to find API references and tutorials, and the version 2 proposal removed the special mechanical meaning of the Optional section and allows replacing the file extension.
Written from the 41 established claims below, then checked against them. How that works.
Documented position14
What the operator of the system says in its own documentation.
The llms.txt proposal at llmstxt.org states that…
- the expectation was that llms.txt would mainly be useful for inference rather than training.
- llms.txt has mainly been used for inference rather than training.
1 quote from 1 source
Our expectation was that llms.txt would mainly be useful for inference rather than training, and that is how it has been used, though training runs could take advantage of the information too.
The llms.txt proposal at llmstxt.org states that…
- llms.txt files are used most heavily for software documentation.
- coding agents follow llms.txt files to find API references and tutorials.
1 quote from 1 source
llms.txt files are used most heavily for software documentation, where coding agents follow them to find API references and tutorials.
- Search Engine Journal published a statement attributed to Google's John Mueller about llms.txt.
- The statement attributed to Google's John Mueller says that no AI system currently uses llms.txt.
- The statement attributed to Google's John Mueller says that server logs make it obvious that no AI system currently uses llms.txt.
2 quotes from 1 source
"FWIW no AI system currently uses llms.txt, [..] It's super-obvious if you look at your server logs. The consumer LLMs / chatbots (the ones that SEOs want traffic from) will fetch your pages – for training and grounding, but none of them fetch the llms.txt file. Maybe they will tomorrow? Maybe I'll win in the lottery tomorrow?"
John Mueller, Google
- How Cats.txt Showed LLMs.txt Evidence Is GEO Astrology searchenginejournal.com
Google Search Central's documentation states, under a heading naming LLMS.txt files, that Google Search itself does not use machine readable files, AI text files, markup or Markdown created to appear in Google Search.
1 quote from 1 source
LLMS.txt files and other "special" markup: You don't need to create new machine readable files, AI text files, markup, or Markdown to appear in Google Search (including its generative AI capabilities), as Google Search itself doesn't use them.
Google's Chrome for Developers Lighthouse documentation describes the llms.txt file as…
- an emerging convention.
- used to provide a machine-readable summary of a website's content.
- designed for LLMs and AI agents.
1 quote from 1 source
The llms.txt file is an emerging convention used to provide a machine-readable summary of a website's content, specifically designed for LLMs and AI agents.
Google's Chrome for Developers Lighthouse documentation…
- states that providing an llms.txt file is optional at the moment.
- marks the audit Not Applicable when the llms.txt file returns a 404.
1 quote from 1 source
If the file is not provided by the server (resulting in a 404), the audit is marked as Not Applicable (N/A), as providing the file is optional at the moment.
Google's Chrome for Developers Lighthouse documentation states that without an llms.txt file, agents may spend more time crawling a site to understand its high-level structure and primary content.
1 quote from 1 source
Without this file, agents may spend more time crawling the site to understand its high-level structure and primary content.
Measured finding15
Something someone actually measured, with the method attached.
Search Engine Journal reports that Ahrefs…
- analyzed logs from 137,000 domains.
- found that 97% of llms.txt files got zero requests.
1 quote from 1 source
Ahrefs analyzed logs from 137,000 domains and found 97% of llms.txt files got zero requests. No bots, no humans.
Search Engine Journal reports that…
- around 28% of the 137,000 domains in the Ahrefs llms.txt analysis publish an llms.txt file.
- llms.txt adoption on the broader web is likely lower than the 28% rate in the Ahrefs llms.txt analysis because Ahrefs' customers are more technical.
1 quote from 1 source
Around 28% of 137,000 domains publish an llms.txt file, but since Ahrefs' customers are more technical, the actual adoption on the broader web is likely lower.
Search Engine Journal reports that in the Ahrefs llms.txt analysis…
- roughly 38,000 domains had valid llms.txt files.
- only about 1,100 of the roughly 38,000 domains with valid llms.txt files received any traffic.
1 quote from 1 source
Of roughly 38,000 domains with valid files, only about 1,100 received any traffic.
In the Ahrefs llms.txt analysis, AI retrieval bots linked to ChatGPT and Perplexity made up 1% of requests to llms.txt files.
1 quote from 1 source
Of files with requests, 96% came from bots, mostly non-AI. AI retrieval bots linked to ChatGPT and Perplexity made up 1%.
Search Engine Journal reports that in the Ahrefs llms.txt analysis, 12% of requests to llms.txt files came from tools that audit, scan or study the files rather than use them.
1 quote from 1 source
The report found 12% of requests from tools that audit, scan, or study llms.txt files rather than use them.
Search Engine Journal reports that in the Ahrefs llms.txt analysis, Slackbot alone fetched llms.txt files more often than PerplexityBot did.
1 quote from 1 source
Slackbot alone fetched llms.txt files more often than PerplexityBot did.
- The Ahrefs llms.txt analysis measured requests rather than whether bots acted on what they fetched.
- Every figure in the Ahrefs llms.txt analysis report is a ceiling.
1 quote from 1 source
Every figure in this report is a ceiling. Ahrefs measured requests, not whether bots acted on what they fetched.
Requests for /llms.txt paths returning 404 errors drew no AI traffic in the Ahrefs analysis.
1 quote from 1 source
Requests for /llms.txt paths with 404 errors drew no AI traffic.
The Chrome Lighthouse llms.txt audit generated…
- about 22 requests across the Ahrefs dataset.
- roughly 1 in 1,000 requests across the Ahrefs dataset.
1 quote from 1 source
The Chrome Lighthouse llms.txt audit, which reignited the llms.txt debate in May, generated about 22 requests across the dataset, roughly 1 in 1,000.
SE Ranking's analysis of 300,000 domains showed no connection between having an llms.txt file and AI citation frequency.
1 quote from 1 source
SE Ranking's earlier analysis of 300,000 domains showed no connection between having llms.txt and AI citation frequency.
Practical effect2
What is observed to happen in practice, as distinct from what is documented.
Google Search Central's documentation states that…
- creating and maintaining LLMS.txt files will neither harm nor help a site's visibility or rankings in Google Search.
- Google Search ignores LLMS.txt files.
1 quote from 1 source
It's completely fine if you decide to create and maintain LLMS.txt files (or other similar files) for other services or systems that use these files. Doing so will neither harm nor help your site's visibility or rankings in Google Search, as Google Search ignores them.
Changed on5
A dated change. This is where advice quietly stops being true.
The llms.txt proposal published at llmstxt.org was revised to version 2 in August 2026.
2 quotes from 1 source
v2 (August 2026)
The original llms.txt proposal was published in September 2024, when the idea that language models would routinely read websites was still speculative.
Version 2 of the llms.txt proposal removed the special mechanical meaning of the Optional section.
1 quote from 1 source
The context-expansion tooling is no longer part of the proposal, and with it goes the special meaning of the Optional section, which told those tools what to omit. Optional sections are still allowed, and remain a useful convention for secondary links, but they no longer carry mechanical semantics.
- Version 1 of the llms.txt proposal specified only one URL form for markdown versions of pages, with .md appended to the full page URL.
- Version 2 of the llms.txt proposal allows replacing the extension.
1 quote from 1 source
v1 specified one URL form for markdown versions, .md appended to the full page URL (page.html.md). Some publishing tools instead replace the extension (page.md), so v2 allows both.
Google added a note to its AI optimization guide clarifying Google Search's usage of llms.txt files on June 15, 2026.
4 quotes from 1 source
June 2026
June 15
Clarifying guidance on llms.txt files
What: Added a note to the AI optimization guide clarifying Google Search's usage of llms.txt files.
Disputed between sources2
Sources that do not agree, presented without picking a winner.
- Google's Chrome for Developers Lighthouse documentation instructs site owners to create an llms.txt file in their website's root directory.
- Google Search Central's guide to optimizing for generative AI features on Google Search tells site owners they can ignore creating AI text files like llms.txt.
3 quotes from 2 sources
Create an llms.txt file and place it in the root directory of your website (for example, https://example.com/llms.txt). The file should follow the llms.txt specification and provide a concise Markdown summary of your site's purpose and key links.
Optimizing your website for generative AI features on Google Search
Prioritize effective SEO strategies over "AEO/GEO hacks": For Google Search, you can ignore tactics like "chunking" content, creating unnecessary AI text files (like llms.txt), or pursuing inauthentic mentions.
Echoed without a primary source3
Widely repeated in the field, but traceable only to other repetitions. Listed because knowing something is merely echoed is worth as much as knowing it is documented.
Search Engine Journal asserts that large studies show no measurable citation advantage for sites that add an llms.txt file.
1 quote from 1 source
a finding since echoed by other large studies showing no measurable citation advantage for sites that add one
- How Cats.txt Showed LLMs.txt Evidence Is GEO Astrology searchenginejournal.com
Search Engine Journal's account reported that cats.txt passed all four proofs commonly cited for llms.txt.
1 quote from 1 source
Then, I checked it against the exact four "proofs" people cite for llms.txt. It passed all four.
- How Cats.txt Showed LLMs.txt Evidence Is GEO Astrology searchenginejournal.com
Search Engine Journal published the argument that a crawler fetching llms.txt tells you nothing about whether the contents of llms.txt are read, weighted, trusted or acted upon.
1 quote from 1 source
A crawler fetching a file tells you nothing about whether the contents are read, weighted, trusted, or acted upon. Fetching things is the entire job description of a crawler.
- How Cats.txt Showed LLMs.txt Evidence Is GEO Astrology searchenginejournal.com
Refused11
Claims the research produced that the grounding gate would not accept, with its reason. They are here because a site that only shows what passed gives you no way to judge whether the gate does anything.
Show what was refused
The llms.txt proposal published at llmstxt.org was originally published in September 2024.
Refused: Quote confirms original publication in September 2024, but does not mention llmstxt.org as the publication venue.
Unsupported: published at llmstxt.org
What it rested on
v2 (August 2026)
The original llms.txt proposal was published in September 2024, when the idea that language models would routinely read websites was still speculative.
Version 2 of the llms.txt proposal removed the context-expansion tooling from the proposal.
Refused: Quote says tooling is no longer part, but does not mention Version 2.
Unsupported: Version 2
What it rested on
The context-expansion tooling is no longer part of the proposal, and with it goes the special meaning of the Optional section, which told those tools what to omit. Optional sections are still allowed, and remain a useful convention for secondary links, but they no longer carry mechanical semantics.
Version 1 of the llms.txt proposal had used the Optional section to tell context-expansion tools what to omit.
Refused: The quote states the Optional section previously told context-expansion tools what to omit but does not mention Version 1 specifically, so the claim overreaches by attributing it to that version.
Unsupported: Version 1
What it rested on
The context-expansion tooling is no longer part of the proposal, and with it goes the special meaning of the Optional section, which told those tools what to omit. Optional sections are still allowed, and remain a useful convention for secondary links, but they no longer carry mechanical semantics.
Google's Search Central changelog states that the June 2026 llms.txt clarification was made to address questions from the community.
Refused: The quotes mention 'these files' and the reason, but none explicitly names llms.txt, so the specific llms.txt clarification is not established by the cited text.
Unsupported: llms.txt
What it rested on
June 2026
June 15
Why: To address questions from the community and clarify that while these files aren't needed for Google Search (and won't negatively or positively impact your visibility or rankings), it's fine if you want to maintain these files for other services or systems that use them.
Google's Search Central changelog states that the June 2026 llms.txt clarification clarifies that llms.txt files aren't needed for Google Search.
Refused: The quoted clarification says 'these files' but never names llms.txt.
Unsupported: llms.txt
What it rested on
June 2026
June 15
Why: To address questions from the community and clarify that while these files aren't needed for Google Search (and won't negatively or positively impact your visibility or rankings), it's fine if you want to maintain these files for other services or systems that use them.
Google's Search Central changelog states that the June 2026 llms.txt clarification clarifies that llms.txt files won't negatively or positively impact visibility or rankings.
Refused: The quotes establish a June 2026 clarification that 'these files' won't affect visibility or rankings, but none of the cited text names llms.txt.
Unsupported: llms.txt
What it rested on
June 2026
June 15
Why: To address questions from the community and clarify that while these files aren't needed for Google Search (and won't negatively or positively impact your visibility or rankings), it's fine if you want to maintain these files for other services or systems that use them.
Google added its guide on optimizing for generative AI features on Search to llms.txt on May 15, 2026.
Refused: The quotes establish the guide and date but never mention llms.txt.
Unsupported: to llms.txt
What it rested on
May 2026
May 15
Adding a new guide on optimizing for generative AI features
What: Added a new guide on optimizing for generative AI features on Search. Notable new sections include guidance on the importance of providing non-commodity content, tips about providing local, shopping, image, and video content, mythbusting common "AEO/GEO" misconceptions, initial guidance on AI agents, and more information on why SEO best practices continue to be relevant for success in our generative AI features on Search.
The guide Google added to llms.txt includes mythbusting of common AEO/GEO misconceptions.
Refused: The quote says Google added a guide on Search with mythbusting, but does not mention llms.txt.
Unsupported: to llms.txt
What it rested on
May 2026
May 15
Adding a new guide on optimizing for generative AI features
What: Added a new guide on optimizing for generative AI features on Search. Notable new sections include guidance on the importance of providing non-commodity content, tips about providing local, shopping, image, and video content, mythbusting common "AEO/GEO" misconceptions, initial guidance on AI agents, and more information on why SEO best practices continue to be relevant for success in our generative AI features on Search.
Search Engine Journal described the Ahrefs llms.txt log analysis with a sample size of 137,000 domains in a June 2026 news article.
Refused: The quotes support SEJ reporting the 137,000-domain Ahrefs log analysis, but none gives the June 2026 date the claim asserts.
Unsupported: June 2026 news article
What it rested on
Ahrefs analyzed logs from 137,000 domains and found 97% of llms.txt files got zero requests. No bots, no humans.
Ahrefs ran the numbers across 100,000 domains and found that the file is, in practice, largely ignored by the crawlers it is meant to court, a finding since echoed by other large studies showing no measurable citation advantage for sites that add one.
Search Engine Journal described the Ahrefs llms.txt log analysis with a sample size of 100,000 domains in an August 2026 column.
Refused: The quotes confirm Search Engine Journal described an Ahrefs analysis across 100,000 domains, but none states or entails an August 2026 date.
Unsupported: August 2026 column
What it rested on
Ahrefs analyzed logs from 137,000 domains and found 97% of llms.txt files got zero requests. No bots, no humans.
Ahrefs ran the numbers across 100,000 domains and found that the file is, in practice, largely ignored by the crawlers it is meant to court, a finding since echoed by other large studies showing no measurable citation advantage for sites that add one.
Search Engine Journal published an account of a deliberately invented file format called cats.txt being tested against the four proofs commonly cited for llms.txt.
Refused: The quote shows something checked against the four proofs but does not state that cats.txt was a deliberately invented file format.
Unsupported: deliberately invented file format called cats.txt
What it rested on
Then, I checked it against the exact four "proofs" people cite for llms.txt. It passed all four.