Who blocks AI · #309 in the Majestic Million

robots.txt · checked 9 Nov 2026

Does noaa.gov block AI crawlers?

No. noaa.gov’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: www.noaa.gov/robots.txt · 92 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 www.noaa.gov/robots.txt · 92 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/*.gif

23Allow: /core/*.jpg

24Allow: /core/*.jpeg

25Allow: /core/*.png

26Allow: /core/*.svg

27Allow: /profiles/*.css$

28Allow: /profiles/*.css?

29Allow: /profiles/*.js$

30Allow: /profiles/*.js?

31Allow: /profiles/*.gif

32Allow: /profiles/*.jpg

33Allow: /profiles/*.jpeg

34Allow: /profiles/*.png

35Allow: /profiles/*.svg

36# Directories

37Disallow: /core/

38Disallow: /profiles/

39# Files

40Disallow: /README.md

41Disallow: /composer/Metapackage/README.txt

42Disallow: /composer/Plugin/ProjectMessage/README.md

43Disallow: /composer/Plugin/Scaffold/README.md

44Disallow: /composer/Plugin/VendorHardening/README.txt

45Disallow: /composer/Template/README.txt

46Disallow: /modules/README.txt

47Disallow: /sites/README.txt

48Disallow: /themes/README.txt

49Disallow: /web.config

50# Paths (clean URLs)

51Disallow: /admin/

52Disallow: /comment/reply/

53Disallow: /filter/tips

54Disallow: /node/add/

55Disallow: /search/

56Disallow: /user/register

57Disallow: /user/password

58Disallow: /user/login

59Disallow: /user/logout

60Disallow: /media/oembed

61Disallow: /*/media/oembed

62# Paths (no clean URLs)

63Disallow: /index.php/admin/

64Disallow: /index.php/comment/reply/

65Disallow: /index.php/filter/tips

66Disallow: /index.php/node/add/

67Disallow: /index.php/search/

68Disallow: /index.php/user/password

69Disallow: /index.php/user/register

70Disallow: /index.php/user/login

71Disallow: /index.php/user/logout

72Disallow: /index.php/media/oembed

73Disallow: /index.php/*/media/oembed

75# Do not follow facets links

76Disallow: /*?f[*

77Disallow: /*?f%5B*

78Disallow: /*&f[*

79Disallow: /*&f%5B*

80# Do not follow image download links

81Disallow: /media/image_download/*

82Disallow: /media/ngdl/download-photo/*

83# Do not follow Digital Collection Search pages

84Disallow: /digital-collections/search/

85# Do not crawl the core /node listing. It is not linked from anywhere on the

86# site (the front page is /node/5) and its pager exposes ~440 pages of teasers.

87# /node/123 canonical paths are deliberately still allowed.

88Disallow: /node$

89Disallow: /node?

90Disallow: /index.php/node$

91Disallow: /index.php/node?

What do the bots actually get?

This page reads robots.txt, which states what noaa.gov 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 noaa.gov Test a path in the robots.txt tester

History

19 October 2026: first checked, robots.txt couldn’t be read.
2 November 2026: robots.txt readable again.

Questions

Does noaa.gov block GPTBot?

No. noaa.gov’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 noaa.gov block ClaudeBot?

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

Does noaa.gov block Google-Extended?

No. noaa.gov’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 noaa.gov block PerplexityBot?

No. noaa.gov’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 noaa.gov?

Yes. noaa.gov’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.