---
title: "Does llms.txt do anything? Three studies say mostly no"
url: https://seomadman.com/studies/llms-txt-measured-traffic-impact
section: studies
published: 2026-09-03T00:00:00.000Z
modified: 2026-09-03T00:00:00.000Z
author: Adam Hafez
topics: ["AI search"]
---

# Does llms.txt do anything? Three studies say mostly no

## The short answer

Three independent checks asked whether llms.txt changes anything measurable, not how many sites have one. Ahrefs found 97% of ~38,360 valid files got zero AI-bot requests in May 2026. Search Engine Land tracked 10 sites for 90 days and found no traffic change in 8. A lone +11% citation figure carries its own author-stated confound.

## Key takeaways

- Ahrefs' server-log analysis found 97% of roughly 38,360 domains with a valid llms.txt file received zero AI-bot requests for it in May 2026.
- Search Engine Land tracked 10 sites for 90 days before and after adding llms.txt and found no measurable traffic change in 8 of them.
- The two Search Engine Land sites that grew did so from new functional content, not from the file itself, per the article's own analysis.
- An independent researcher measured an 11% citation lift on Claude and Perplexity across four properties, then said plainly his design cannot attribute it cleanly to llms.txt.
- No study reviewed here isolates llms.txt as the sole cause of any change, which is a different and harder question than whether sites publish one at all.

Two pieces on this site have already asked who publishes an llms.txt file. Our [adoption
study](/studies/llms-txt-adoption-2026) found 14 of 60 major sites serve one, concentrated among
SEO vendors and developer platforms. Our [tracker comparison](/reports/llms-txt-adoption-tracker-comparison)
showed five trackers disagreeing on the adoption rate because none measured the same population.
Neither piece asked the harder question: once a file exists on a server, does anything read it,
and does having one change what an AI system does with the site. Three separate checks published
in 2026 answer that question, and the answer is mostly no.

## The usage gap Ahrefs found underneath its own adoption number

Ahrefs' analysis of 137,210 domains running its Web Analytics or Bot Analytics product found 28%
serve a valid llms.txt file, roughly 38,360 domains, a figure already used in our tracker
comparison. The same report goes further, checking server logs for whether anything actually
requested those files. In May 2026, 97% of the roughly 38,360 valid files received zero requests.
Ahrefs is explicit that even the remaining 3% is a ceiling on real usage, not a floor: a fetch does
not mean the content was read or acted on, since "many bots may have fetched the llms.txt file
without ever acting on what's inside." A file that nothing requests cannot be doing anything for
the site that published it, which makes the adoption question and the usage question genuinely
different findings, not two ways of stating the same one.

## Two small tests, two honest limitations

Search Engine Land tracked 10 sites across finance, B2B SaaS, ecommerce, insurance and pet care,
measuring AI traffic and crawl frequency for 90 days before and after adding llms.txt. Eight sites
showed no measurable change. One declined 19.7%, a drop the piece attributes to unrelated causes.
Two grew, 25% and 12.5%, but the article's own analysis credits that growth to new functional
content the sites published alongside the file, not to the file itself: "llms.txt documented those
efforts. It didn't drive them." A 10-site sample cannot settle the question for the whole web, and
the piece does not claim it does.

The one positive figure in this space comes from an independent researcher who tracked citations
across four of his own properties over 90 days and measured an 11% overall lift after publishing
llms.txt, concentrated almost entirely on Claude and Perplexity with no movement on ChatGPT Search
or Google AI Overviews. He then undercut his own headline number in the same piece: "my +11%
observation came from a window in which several changes shipped together, so the design does not
support attributing it cleanly to llms.txt." That sentence is the reason this figure belongs in
this piece at all. A researcher willing to name the hole in his own methodology, on a corpus he
controls, is more useful than a cleaner-looking number from someone who did not check.

## Why we care

**Adoption and impact are two different claims, and only one of them has evidence behind it right
now.** Fourteen sites in sixty publishing a file, per our adoption study, tells you nothing about
whether the file did anything once published. The usage and traffic data above is the actual
answer to that second question, and it is a weak one: near-total non-use in the large sample,
no effect in most of the small traffic test, and a positive citation number its own author will
not stand behind without a caveat.

**If a vendor pitches llms.txt as a traffic or citation lever, ask which of these three studies
they are relying on.** None of the three supports a clean causal claim. The Ahrefs number shows the
file mostly sits unread. The Search Engine Land test shows no effect in 8 of 10 real sites. The one
number that moved comes from a researcher who told you himself not to trust it as isolated evidence,
which is the standard every figure in [AI search](/topics/ai-search) coverage should be held to
before it goes in a deck.

## Frequently asked questions

### Does publishing llms.txt increase AI citations or traffic?

The best evidence available says usually not. Ahrefs found 97% of published files never get requested at all, and Search Engine Land's 10-site traffic test found no measurable change in 8 cases. One independent researcher measured an 11% citation lift, but stated himself that his own study design cannot attribute it cleanly to the file.

### Is this the same finding as the site's llms.txt adoption research?

No. Our [adoption study](/studies/llms-txt-adoption-2026) and [tracker comparison](/reports/llms-txt-adoption-tracker-comparison) both measure who publishes a file. This piece asks a separate question: whether publishing one changes anything an AI bot does afterward.

### Why trust an 11% figure the author himself calls confounded?

We are not treating 11% as a clean effect size. We are citing it because the author's own stated limitation, that several changes shipped in the same 90-day window and his design cannot isolate llms.txt from them, is the same honesty this site's sourcing rule requires, and it is a more useful data point with that caveat attached than without it.

## Sources

1. [We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read](https://ahrefs.com/blog/llmstxt-study/) - Ahrefs (primary)
2. [Does llms.txt matter? We tracked 10 sites to find out](https://searchengineland.com/does-llms-txt-matter-467740) - Search Engine Land (primary)
3. [The GEO Measurement Study: 50,000 AI Citations in 90 Days, What Actually Moves Citation Share](https://guptadeepak.com/the-geo-measurement-study-50000-ai-citations-in-90-days-what-actually-moves-citation-share/) - Deepak Gupta