Who blocks AI · #719 in the Majestic Million

robots.txt · checked 9 Nov 2026

Does iop.org block AI crawlers?

No. iop.org’s robots.txt lets all 19 AI crawlers we track crawl the site. Search engines such as Googlebot and Bingbot may crawl it.

GPTBotAllowed OAI-SearchBotAllowed ClaudeBotAllowed PerplexityBotAllowed Google-ExtendedAllowed CCBotAllowed

robots.txt: iop.org/robots.txt · 79 lines
llms.txt: none
Checked: 9 November 2026, as canaicrawl. We check again every week.

Every bot, and the line that decides

Search engines

Bot	Operator	robots.txt	Deciding line
`Googlebot`	Google	Allowed	no rule matches the home page
`Bingbot`	Microsoft	Allowed	no rule matches the home page
`DuckDuckBot`	DuckDuckGo	Allowed	no rule matches the home page
`Applebot`	Apple	Allowed	no rule matches the home page
`PetalBot`	Huawei	Allowed	no rule matches the home page
`YandexBot`	Yandex	Allowed	no rule matches the home page
`Baiduspider`	Baidu	Allowed	no rule matches the home page

AI search

Bot	Operator	robots.txt	Deciding line
`OAI-SearchBot`	OpenAI	Allowed	no rule matches the home page
`PerplexityBot`	Perplexity	Allowed	no rule matches the home page
`Claude-SearchBot`	Anthropic	Allowed	no rule matches the home page
`DuckAssistBot`	DuckDuckGo	Allowed	no rule matches the home page
`Amazonbot`	Amazon	Allowed	no rule matches the home page
`YouBot`	You.com	Allowed	no rule matches the home page

AI training

Bot	Operator	robots.txt	Deciding line
`GPTBot`	OpenAI	Allowed	no rule matches the home page
`ClaudeBot`	Anthropic	Allowed	no rule matches the home page
`Google-Extended`	Google	Allowed	no rule matches the home page
`CCBot`	Common Crawl	Allowed	no rule matches the home page
`Applebot-Extended`	Apple	Allowed	no rule matches the home page
`GoogleOther`	Google	Allowed	no rule matches the home page
`Meta-ExternalAgent`	Meta	Allowed	no rule matches the home page
`Bytespider`	ByteDance	Allowed	no rule matches the home page

User-triggered fetchers

Bot	Operator	robots.txt	Deciding line
`ChatGPT-User`	OpenAI	Allowed	no rule matches the home page
`Claude-User`	Anthropic	Allowed	no rule matches the home page
`Perplexity-User`	Perplexity	Allowed	no rule matches the home page
`MistralAI-User`	Mistral	Allowed	no rule matches the home page
`Meta-ExternalFetcher`	Meta	Allowed	no rule matches the home page

SEO tools

Bot	Operator	robots.txt	Deciding line
`AhrefsBot`	Ahrefs	Allowed	no rule matches the home page
`SemrushBot`	Semrush	Allowed	no rule matches the home page
`MJ12bot`	Majestic	Allowed	no rule matches the home page
`DotBot`	Moz	Allowed	no rule matches the home page

View iop.org/robots.txt · 79 lines

2# robots.txt

4# This file is to prevent the crawling and indexing of certain parts

5# of your site by web crawlers and spiders run by sites like Yahoo!

6# and Google. By telling these "robots" where not to go on your site,

7# you save bandwidth and server resources.

9# This file will be ignored unless it is at the root of your host:

10# Used: http://example.com/robots.txt

11# Ignored: http://example.com/site/robots.txt

12#

13# For more information about the robots.txt standard, see:

14# http://www.robotstxt.org/robotstxt.html

16User-agent: *

17# CSS, JS, Images

18Allow: /core/*.css$

19Allow: /core/*.css?

20Allow: /core/*.js$

21Allow: /core/*.js?

22Allow: /core/*.avif

23Allow: /core/*.gif

24Allow: /core/*.jpg

25Allow: /core/*.jpeg

26Allow: /core/*.png

27Allow: /core/*.svg

28Allow: /core/*.webp

29Allow: /profiles/*.css$

30Allow: /profiles/*.css?

31Allow: /profiles/*.js$

32Allow: /profiles/*.js?

33Allow: /profiles/*.avif

34Allow: /profiles/*.gif

35Allow: /profiles/*.jpg

36Allow: /profiles/*.jpeg

37Allow: /profiles/*.png

38Allow: /profiles/*.svg

39Allow: /profiles/*.webp

40# Directories

41Disallow: /core/

42Disallow: /profiles/

43# Files

44Disallow: /README.md

45Disallow: /composer/Metapackage/README.txt

46Disallow: /composer/Plugin/ProjectMessage/README.md

47Disallow: /composer/Plugin/Scaffold/README.md

48Disallow: /composer/Plugin/VendorHardening/README.txt

49Disallow: /composer/Template/README.txt

50Disallow: /modules/README.txt

51Disallow: /sites/README.txt

52Disallow: /themes/README.txt

53# Paths (clean URLs)

54Disallow: /admin/

55Disallow: /comment/reply/

56Disallow: /filter/tips

57Disallow: /node/add/

58Disallow: /search/

59Disallow: /search?

60Disallow: /user/register

61Disallow: /user/password

62Disallow: /user/login

63Disallow: /user/logout

64Disallow: /media/oembed

65Disallow: /*/media/oembed

66# Paths (no clean URLs)

67Disallow: /index.php/admin/

68Disallow: /index.php/comment/reply/

69Disallow: /index.php/filter/tips

70Disallow: /index.php/node/add/

71Disallow: /index.php/search/

72Disallow: /index.php/search?

73Disallow: /index.php/user/password

74Disallow: /index.php/user/register

75Disallow: /index.php/user/login

76Disallow: /index.php/user/logout

77Disallow: /index.php/media/oembed

78Disallow: /index.php/*/media/oembed

What do the bots actually get?

This page reads robots.txt, which states what iop.org asks of crawlers. A firewall or CDN can still refuse a bot that robots.txt allows. The live check requests the page as each bot and shows the status it gets.

Run a live check on iop.org Test a path in the robots.txt tester

History

19 October 2026: first checked.

Questions

Does iop.org block GPTBot?

No. iop.org’s robots.txt lets GPTBot crawl the site. GPTBot is OpenAI’s crawler for training data; blocking it doesn’t affect ChatGPT search, which uses OAI-SearchBot. Checked 9 November 2026.

Does iop.org block ClaudeBot?

No. iop.org’s robots.txt lets ClaudeBot crawl the site. ClaudeBot is Anthropic’s crawler for training data. Checked 9 November 2026.

Does iop.org block Google-Extended?

No. iop.org’s robots.txt lets Google-Extended crawl the site. Google-Extended is the token that controls whether Google may use pages for Gemini training and grounding; it doesn’t affect Google Search. Checked 9 November 2026.

Does iop.org block PerplexityBot?

No. iop.org’s robots.txt lets PerplexityBot crawl the site. PerplexityBot is the crawler that indexes pages for Perplexity’s answers. Checked 9 November 2026.

Can ChatGPT search find iop.org?

Yes. iop.org’s robots.txt lets OAI-SearchBot crawl the site. OAI-SearchBot is the crawler behind ChatGPT search; blocking it keeps the site out of ChatGPT’s search answers. Checked 9 November 2026.