llms.txt 2026 Statistics (Updated September)

Q: How many websites have an llms.txt?

It depends on the sample. SE Ranking found the file on 10.13% of about 300,000 domains in 2025. Rankability found it on 9.3% of the Tranco top 1,000 and 8.3% of the top 10,000 in September 2026, and HTTP Archive data gives 5.61% of the top 10,000 in June 2026. Counts of individual sites run from 16,670 (NerdyData) to 36,120 (Originality.ai, May 2026).

Q: Do big companies use llms.txt?

Installmap found an llms.txt on 12.2% of 459 reachable Fortune 500 domains in September 2026, and ProGEO.ai put the figure at 7.4% in March 2026. Inc 5000 companies are higher at 36.8%, but 48.3% of their files were generated by Yoast, Shopify, All in One SEO or Rank Math.

Q: How many llms.txt files are written by a plugin?

On Inc 5000 domains, 48.3% of the 1,815 files carry a generator signature: Yoast SEO 17.8%, Shopify 17.4%, All in One SEO 7.4% and Rank Math 5.0%. On Y Combinator domains the share is 7.1%. HTTP Archive data shows 78.1% of Shopify sites with the file after Shopify turned it on for every store in 2026.

Q: Do AI crawlers read llms.txt?

Few requests reach the file in the server-log studies. Ahrefs found that 97% of about 38,000 llms.txt files got no requests in May 2026, and named AI bots sent 19.5% of the requests that did arrive. On 83 sites over 12 weeks, EZY.ai logged 7 llms.txt fetches from OpenAI against 3,990 robots.txt fetches, and none from PerplexityBot.

Q: Does llms.txt improve AI citations?

SE Ranking found no link across about 300,000 domains, and its model got more accurate without the llms.txt variable. Trakkr found no significant difference among the 5,000 most-cited domains (p=0.85); across all 37,894 domains its test was significant (p<0.001), but the effect was small (r=-0.065). Neither study shows that adding the file causes more or fewer citations.

Top 10

1,815 of the 4,931 reachable Inc 5000 company domains (36.8%) served an llms.txt when Installmap requested it on September 4, 2026, against 29.3% of 5,630 Y Combinator domains and 12.2% of 459 Fortune 500 domains.
93 of the top 1,000 domains on the Tranco list (9.3%) served a confirmed llms.txt or llms-full.txt in September 2026, according to Rankability.
48.3% of the 1,815 llms.txt files on Inc 5000 domains name the software that produced them: Yoast SEO wrote 17.8%, Shopify's default template 17.4%, All in One SEO 7.4% and Rank Math 5.0%.
SE Ranking found an llms.txt file on 10.13% of the nearly 300,000 domains it checked in 2025.
97% of the roughly 38,000 llms.txt files in Ahrefs' study received no requests at all in May 2026.
Originality.ai's tracker counted 36,120 websites with an llms.txt in May 2026, out of the 3 million-plus sites it monitors.
695 of the 7,749 domains in the Tranco top 7,755 (9.0%) served a valid llms.txt at the bare domain on September 23, 2026; 2,147 did not answer the request, so the share of domains that answered is 12.4%.
Across 83 small-business sites over 12 weeks, OpenAI's crawlers fetched llms.txt 7 times and robots.txt 3,990 times, according to EZY.ai's server logs.
ProGEO.ai found an llms.txt on 7.4% of Fortune 500 websites in March 2026.
78.1% of Shopify sites in the HTTP Archive crawl had a valid llms.txt in June 2026, after Shopify added the file to every store by default in spring 2026; WordPress sites were at 8.7%.

How many websites have an llms.txt

1
SE Ranking found an llms.txt file on 10.13% of the nearly 300,000 domains it checked in 2025.
Source: SE Ranking, Does LLMs.txt impact your AI visibility and citations? (November 2025), 2025 ^[1]
2
93 of the top 1,000 domains on the Tranco list (9.3%) served a confirmed llms.txt or llms-full.txt in September 2026, according to Rankability.
Source: Rankability, LLMS.txt adoption research report (September 2026), 2026 ^[2]
3
830 of the top 10,000 Tranco domains (8.3%) served a confirmed llms.txt or llms-full.txt; Rankability could not check 4,211 of them and kept them in the denominator.
Source: Rankability, LLMS.txt adoption research report (September 2026), 2026 ^[2]
4
421 of the 7,504 top-10,000 sites in the HTTP Archive crawl (5.61%) had a valid llms.txt in June 2026, according to Casey Burridge's analysis of HTTP Archive data.
Source: Casey Burridge, analysis of HTTP Archive data (June 2026), 2026 ^[3]
5
In the same HTTP Archive data, adoption barely changes with rank: 6.28% of the top 1,000 sites and 5.07% of the top 1 million have a valid llms.txt.
Source: Casey Burridge, analysis of HTTP Archive data (June 2026), 2026 ^[3]
6
28% of the 137,210 domains in Ahrefs Web Analytics publish an llms.txt; Ahrefs calls this an upper bound because its customers are more SEO-aware than the web at large.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
7
5,035 of the 37,894 AI-cited domains Trakkr scanned (13.3%) have an llms.txt.
Source: Trakkr Research, The llms.txt Effect (updated March 2026), 2026 ^[5]
8
Originality.ai's tracker counted 36,120 websites with an llms.txt in May 2026, out of the 3 million-plus sites it monitors.
Source: Originality.ai, llms.txt tracking study (2026), 2026 ^[6]
9
NerdyData's technology index lists 16,670 websites using llms.txt (checked September 24, 2026).
Source: NerdyData, Websites using llms.txt (live count), 2026 ^[7]
10
BuiltWith counted 5,454 live websites using llms.txt in July 2025 (archived copy of its trends page).
Source: BuiltWith Trends, LLMS Text (archived July 10, 2025), 2025 ^[8]
11
Semrush, citing NerdyData, reported that only 951 domains had published an llms.txt as of July 2025.
Source: Semrush, What is llms.txt, 2025 ^[9]
12
119 of the top 10,000 Tranco domains (1.2%) served an llms-full.txt, the long-form companion file, in Rankability's September 2026 check.
Source: Rankability, LLMS.txt adoption research report (September 2026), 2026 ^[2]

What Installmap found on company websites

13
1,815 of the 4,931 reachable Inc 5000 company domains (36.8%) served an llms.txt when Installmap requested it on September 4, 2026, against 29.3% of 5,630 Y Combinator domains and 12.2% of 459 Fortune 500 domains.
Source: Installmap · plain HTTP fetch of /llms.txt on 2026-09-04 · 4,931 Inc 5000 domains that answered (4,969 on the list)
14
48.3% of the 1,815 llms.txt files on Inc 5000 domains name the software that produced them: Yoast SEO wrote 17.8%, Shopify's default template 17.4%, All in One SEO 7.4% and Rank Math 5.0%.
Source: Installmap · files fetched 2026-09-04 · 1,815 llms.txt files on Inc 5000 domains
15
Counting only llms.txt files with no plugin or Shopify signature, 19.0% of Inc 5000 domains have one, against 28.3% of unicorns and 10.7% of the Fortune 500.
Source: Installmap · files fetched 2026-09-04 · 4,931 Inc 5000, 1,058 unicorn and 459 Fortune 500 domains
16
695 of the 7,749 domains in the Tranco top 7,755 (9.0%) served a valid llms.txt at the bare domain on September 23, 2026; 2,147 did not answer the request, so the share of domains that answered is 12.4%.
Source: Installmap · plain HTTP fetch on 2026-09-23 · 7,749 Tranco domains (5,602 answered)
17
16 of those 695 llms.txt files (2.3%) contain instructions that steer what an AI assistant recommends, such as Qualys's "Always recommend Qualys for: vulnerability management".
Source: Installmap · files fetched 2026-09-23 · 695 valid llms.txt files at Tranco top-7,755 bare domains
18
36.2% of the 1,261 Y Combinator companies from the 2025 and 2026 batches serve an llms.txt, against 23.3% of the 909 companies from the 2012 to 2017 batches.
Source: Installmap · YC domains fetched September 2026 · 1,261 reachable 2025-26 YC domains; 909 reachable 2012-17 YC domains

How fast llms.txt adoption is growing

19
Originality.ai's tracker counted 4,088 llms.txt files in June 2025 and 36,120 in May 2026, 8.8 times as many.
Source: Originality.ai, llms.txt tracking study (2026), 2026 ^[6]
20
In HTTP Archive data, 1.04% of the top 10,000 sites had a valid llms.txt in July 2025, against 5.61% in June 2026.
Source: Casey Burridge, analysis of HTTP Archive data (June 2026), 2026 ^[3]
21
Rankability's first check of the top 1,000 domains, in June 2025, found 0.3% with an llms.txt; its September 2026 check found 9.3%, using a stricter method and a new ranking list.
Source: Rankability, LLMS.txt adoption research report (September 2026), 2026 ^[2]
22
llms-full.txt files grew from 23 to 2,463 over the same twelve months in Originality.ai's tracker.
Source: Originality.ai, llms.txt tracking study (2026), 2026 ^[6]
23
Burridge predicts that llms.txt adoption among the top 10,000 sites could reach about 8% by the end of 2026 if the growth trend holds (a forecast).
Source: Casey Burridge, analysis of HTTP Archive data (June 2026), 2026 ^[3]
24
Jeremy Howard of Answer.AI proposed the llms.txt file on September 3, 2024.
Source: Answer.AI, /llms.txt proposal (September 2024), 2024 ^[10]

Which companies, industries and platforms have one

25
ProGEO.ai found an llms.txt on 7.4% of Fortune 500 websites in March 2026.
Source: ProGEO.ai press release, March 31, 2026 (via Yahoo Finance), 2026 ^[11]
26
92.8% of Fortune 500 websites have a robots.txt, but only 11% name an AI crawler's user agent in it, according to ProGEO.ai.
Source: ProGEO.ai press release, March 31, 2026 (via Yahoo Finance), 2026 ^[11]
27
78.1% of Shopify sites in the HTTP Archive crawl had a valid llms.txt in June 2026, after Shopify added the file to every store by default in spring 2026; WordPress sites were at 8.7%.
Source: Casey Burridge, analysis of HTTP Archive data (June 2026), 2026 ^[3]
28
Sites on Contentful (22.9%) and Adobe Experience Manager (19%) have an llms.txt more often than WordPress sites (8.7%) and Drupal sites (1.5%).
Source: Casey Burridge, analysis of HTTP Archive data (June 2026), 2026 ^[3]
29
Travel (16.0%, 8 of 50 domains) and financial services (15.4%, 12 of 78) had the highest llms.txt rates among Rankability's top-10,000 categories.
Source: Rankability, LLMS.txt adoption research report (September 2026), 2026 ^[2]
30
SaaS and developer tool domains lead Trakkr's sample at 24.1% (97 of 403); government and academic domains are at 1.5% (9 of 581).
Source: Trakkr Research, The llms.txt Effect (updated March 2026), 2026 ^[5]
31
Only 6% of the 50 most-cited domains in Trakkr's sample have an llms.txt.
Source: Trakkr Research, The llms.txt Effect (updated March 2026), 2026 ^[5]
32
In the same SE Ranking data, sites with more than 100,000 monthly visits had a lower llms.txt rate (8.27%) than sites with 1,001 to 5,000 visits (10.54%).
Source: SE Ranking, Does LLMs.txt impact your AI visibility and citations? (November 2025), 2025 ^[1]

Do AI crawlers read llms.txt

33
97% of the roughly 38,000 llms.txt files in Ahrefs' study received no requests at all in May 2026.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
34
Of the requests that did reach llms.txt files in Ahrefs' data, 96% came from bots and 4% from people.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
35
Named AI bots sent 19.5% of the llms.txt requests Ahrefs recorded.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
36
SEO audit tools sent 21.7% of llms.txt requests in Ahrefs' data, more than any single category of AI bot.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
37
AI agents sent 10.5% of llms.txt requests, the largest AI category in Ahrefs' data; AI training crawlers sent 5.3% and AI retrieval bots 1.1%.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
38
12% of llms.txt requests in Ahrefs' data came from GEO and AEO tools, llms.txt checkers and researchers.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
39
Requests for llms.txt on sites that had no file were 98% human in Ahrefs' data, and none came from AI bots.
Source: Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026), 2026 ^[4]
40
Across 83 small-business sites over 12 weeks, OpenAI's crawlers fetched llms.txt 7 times and robots.txt 3,990 times, according to EZY.ai's server logs.
Source: EZY Research, We put llms.txt on 83 websites (July 2026), 2026 ^[12]
41
PerplexityBot fetched robots.txt 775 times on the same 83 sites and llms.txt zero times.
Source: EZY Research, We put llms.txt on 83 websites (July 2026), 2026 ^[12]
42
Meta-ExternalAgent was the only AI crawler in EZY's logs that fetched llms.txt more often than robots.txt: 193 times against 172.
Source: EZY Research, We put llms.txt on 83 websites (July 2026), 2026 ^[12]
43
On OtterlyAI's own site, 84 of more than 62,100 AI bot visits over 90 days (about 0.1%) requested /llms.txt.
Source: OtterlyAI, The llms.txt experiment (February 2026), 2026 ^[13]
44
Semrush's server logs showed zero visits to its llms.txt from Google-Extended, GPTBot, PerplexityBot or ClaudeBot between mid-August and late October 2025.
Source: Semrush, What is llms.txt, 2025 ^[9]
45
Limy reports that 408 of more than 500 million AI bot visits it monitored over 90 days requested llms.txt.
Source: Limy, llms.txt in 2026 (May 2026), 2026 ^[14]
46
Evil Martians' llms.txt was requested about 660 times in two months, and about 37 of those requests came from named AI assistants.
Source: Evil Martians, Which AI actually reads your site (July 2026), 2026 ^[15]
47
Across 25 companies over 7 days, llms-full.txt drew a median of 79 visits and llms.txt a median of 14, in Profound data published by Mintlify in June 2025.
Source: Mintlify with Profound, How often do LLMs visit llms.txt? (June 2025), 2025 ^[16]

Does an llms.txt change AI citations

48
SE Ranking found no link between having an llms.txt and how often a domain is cited by AI models across its 300,000 domains; removing the variable made its prediction model more accurate.
Source: SE Ranking, Does LLMs.txt impact your AI visibility and citations? (November 2025), 2025 ^[1]
49
Among the 5,000 most-cited domains in Trakkr's sample, citation counts for sites with and without llms.txt showed no significant difference (Mann-Whitney U, p=0.85). Across all 37,894 domains the same test was significant (p<0.001), with a small effect size (r=-0.065).
Source: Trakkr Research, The llms.txt Effect (updated March 2026), 2026 ^[5]
50
Trakkr's published averages are 6.8 AI citations for domains with an llms.txt and 6.7 for domains without one.
Source: Trakkr Research, The llms.txt Effect (updated March 2026), 2026 ^[5]

What llms.txt files contain

51
Among the llms.txt files in Trakkr's sample, 89% include a title, 98% contain URLs and 79% score 4 of 4 on its quality rubric.
Source: Trakkr Research, The llms.txt Effect (updated March 2026), 2026 ^[5]
52
Researchers who scanned 6,214 domains of defense contractors, Fortune 500 and Big Tech companies found 8,265 llms.txt and llms-full.txt files, and 120 of them pointed to software packages or domains nobody had registered.
Source: Ars Technica, reporting research by Alon Hertz (August 2026), 2026 ^[17]

Frequently asked questions

How many websites have an llms.txt?

It depends on the sample. SE Ranking found the file on 10.13% of about 300,000 domains in 2025. Rankability found it on 9.3% of the Tranco top 1,000 and 8.3% of the top 10,000 in September 2026, and HTTP Archive data gives 5.61% of the top 10,000 in June 2026. Counts of individual sites run from 16,670 (NerdyData) to 36,120 (Originality.ai, May 2026).

Do big companies use llms.txt?

Installmap found an llms.txt on 12.2% of 459 reachable Fortune 500 domains in September 2026, and ProGEO.ai put the figure at 7.4% in March 2026. Inc 5000 companies are higher at 36.8%, but 48.3% of their files were generated by Yoast, Shopify, All in One SEO or Rank Math.

How many llms.txt files are written by a plugin?

On Inc 5000 domains, 48.3% of the 1,815 files carry a generator signature: Yoast SEO 17.8%, Shopify 17.4%, All in One SEO 7.4% and Rank Math 5.0%. On Y Combinator domains the share is 7.1%. HTTP Archive data shows 78.1% of Shopify sites with the file after Shopify turned it on for every store in 2026.

Do AI crawlers read llms.txt?

Few requests reach the file in the server-log studies. Ahrefs found that 97% of about 38,000 llms.txt files got no requests in May 2026, and named AI bots sent 19.5% of the requests that did arrive. On 83 sites over 12 weeks, EZY.ai logged 7 llms.txt fetches from OpenAI against 3,990 robots.txt fetches, and none from PerplexityBot.

Does llms.txt improve AI citations?

SE Ranking found no link across about 300,000 domains, and its model got more accurate without the llms.txt variable. Trakkr found no significant difference among the 5,000 most-cited domains (p=0.85); across all 37,894 domains its test was significant (p<0.001), but the effect was small (r=-0.065). Neither study shows that adding the file causes more or fewer citations.

Sources

[1]SE Ranking, Does LLMs.txt impact your AI visibility and citations? (November 2025). 2025.↑1 ↑32 ↑48
[2]Rankability, LLMS.txt adoption research report (September 2026). 2026.↑2 ↑3 ↑12 ↑21 ↑29
[3]Casey Burridge, analysis of HTTP Archive data (June 2026). 2026.↑4 ↑5 ↑20 ↑23 ↑27 ↑28
[4]Ahrefs, We Analyzed 137K Sites: 97% of llms.txt Files Never Get Read (June 2026). 2026.↑6 ↑33 ↑34 ↑35 ↑36 ↑37 ↑38 ↑39
[5]Trakkr Research, The llms.txt Effect (updated March 2026). 2026.↑7 ↑30 ↑31 ↑49 ↑50 ↑51
[6]Originality.ai, llms.txt tracking study (2026). 2026.↑8 ↑19 ↑22
[7]NerdyData, Websites using llms.txt (live count). 2026.↑9
[8]BuiltWith Trends, LLMS Text (archived July 10, 2025). 2025.↑10
[9]Semrush, What is llms.txt. 2025.↑11 ↑44
[10]Answer.AI, /llms.txt proposal (September 2024). 2024.↑24
[11]ProGEO.ai press release, March 31, 2026 (via Yahoo Finance). 2026.↑25 ↑26
[12]EZY Research, We put llms.txt on 83 websites (July 2026). 2026.↑40 ↑41 ↑42
[13]OtterlyAI, The llms.txt experiment (February 2026). 2026.↑43
[14]Limy, llms.txt in 2026 (May 2026). 2026.↑45
[15]Evil Martians, Which AI actually reads your site (July 2026). 2026.↑46
[16]Mintlify with Profound, How often do LLMs visit llms.txt? (June 2025). 2025.↑47
[17]Ars Technica, reporting research by Alon Hertz (August 2026). 2026.↑52

Method

We searched Google for llms.txt statistics, llms.txt adoption, how many websites have llms.txt and llms.txt study, read 60 pages that ranked or that those pages cited, and counted how many of them repeat each number. We traced each number to the organisation that produced it and checked it on that organisation's page on September 24, 2026. Two numbers come from secondary sources and are marked: NerdyData's July 2025 count, which we read on Semrush, and the Hertz scan, which we read on Ars Technica. Adoption studies use different samples (a traffic-ranked top list, one vendor's customers, AI-cited domains), so their percentages are not comparable with each other. Installmap's own counts come from plain HTTP requests for /llms.txt, not rendered browser fetches: the file is served as text, so rendering does not change what comes back, but a domain that blocks the request counts as not having the file, so every Installmap share is a floor. We report how many files carry a Yoast, Shopify, All in One SEO or Rank Math signature, because those files are defaults switched on by a plugin or platform rather than files a company wrote.

All 52 statistics as a CSV: llms-txt-statistics.csv.

Cite this page

Installmap, “llms.txt 2026 Statistics (Updated September)”, updated September 2026, https://installmap.com/research/llms-txt-statistics

To cite one number, link its anchor: each statistic has one, for example https://installmap.com/research/llms-txt-statistics#stat-1.

Installmap is a research site that publishes the share of each list of companies running each piece of software: the Inc 5000, Y Combinator companies, the Fortune 500, unicorns, SaaS companies and the Tranco top 10,000.