Who blocks AI · #430 in the Majestic Million

robots.txt · checked 9 Nov 2026

Does arstechnica.com block AI crawlers?

Yes. arstechnica.com’s robots.txt blocks 16 of the 19 AI crawlers we track, including ClaudeBot, Google-Extended, PerplexityBot and 13 more. It also blocks PetalBot among search engines.

GPTBotAllowed OAI-SearchBotAllowed ClaudeBotBlocked PerplexityBotBlocked Google-ExtendedBlocked CCBotBlocked

robots.txt: arstechnica.com/robots.txt · 85 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	Blocked	line 45 · `Disallow: /` under `User-agent: PetalBot`
`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	Blocked	line 45 · `Disallow: /` under `User-agent: PerplexityBot`
`Claude-SearchBot`	Anthropic	Blocked	line 45 · `Disallow: /` under `User-agent: Claude-SearchBot`
`DuckAssistBot`	DuckDuckGo	Blocked	line 45 · `Disallow: /` under `User-agent: DuckAssistBot`
`Amazonbot`	Amazon	Blocked	line 48 · `Disallow: /` under `User-agent: Amazonbot`
`YouBot`	You.com	Blocked	line 45 · `Disallow: /` under `User-agent: YouBot`

AI training

Bot	Operator	robots.txt	Deciding line
`GPTBot`	OpenAI	Allowed	no rule matches the home page
`ClaudeBot`	Anthropic	Blocked	line 45 · `Disallow: /` under `User-agent: ClaudeBot`
`Google-Extended`	Google	Blocked	line 45 · `Disallow: /` under `User-agent: Google-Extended`
`CCBot`	Common Crawl	Blocked	line 45 · `Disallow: /` under `User-agent: CCBot`
`Applebot-Extended`	Apple	Blocked	line 45 · `Disallow: /` under `User-agent: Applebot-Extended`
`GoogleOther`	Google	Blocked	line 45 · `Disallow: /` under `User-agent: GoogleOther`
`Meta-ExternalAgent`	Meta	Blocked	line 45 · `Disallow: /` under `User-agent: meta-externalagent`
`Bytespider`	ByteDance	Blocked	line 45 · `Disallow: /` under `User-agent: Bytespider`

User-triggered fetchers

Bot	Operator	robots.txt	Deciding line
`ChatGPT-User`	OpenAI	Allowed	no rule matches the home page
`Claude-User`	Anthropic	Blocked	line 45 · `Disallow: /` under `User-agent: Claude-User`
`Perplexity-User`	Perplexity	Blocked	line 45 · `Disallow: /` under `User-agent: Perplexity-User`
`MistralAI-User`	Mistral	Blocked	line 45 · `Disallow: /` under `User-agent: MistralAI-User`
`Meta-ExternalFetcher`	Meta	Blocked	line 45 · `Disallow: /` under `User-agent: meta-externalfetcher`

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 arstechnica.com/robots.txt · 85 lines

1Sitemap: https://arstechnica.com/sitemap.xml

3# Google Image

4User-agent: Googlebot-Image

5Disallow:

6Allow: /*

8# Google AdSense

9User-agent: Mediapartners-Google*

10Disallow:

12User-agent: Google-Extended

13User-agent: Google-CloudVertexBot

14User-agent: GoogleOther

15User-agent: Applebot-Extended

16User-agent: meta-webindexer

17User-agent: meta-externalagent

18User-agent: meta-externalfetcher

19User-agent: ClaudeBot

20User-agent: Claude-SearchBot

21User-agent: Claude-User

22User-agent: PerplexityBot

23User-agent: Perplexity-User

24User-agent: cohere-training-data-crawler

25User-agent: cohere-ai

26User-agent: CCBot

27User-agent: PanguBot

28User-agent: PetalBot

29User-agent: Bytespider

30User-agent: Diffbot

31User-agent: DuckAssistBot

32User-agent: MistralAI-User

33User-agent: Timpibot

34User-agent: Webzio

35User-agent: Webzio-Extended

36User-agent: archive.org_bot

37User-agent: ia_archiver

38User-agent: ia_archiver-web.archive.org

39User-agent: heritrix

40User-agent: anthropic-ai

41User-agent: Claude-Web

42User-agent: FacebookBot

43User-agent: Omgilibot

44User-agent: YouBot

45Disallow: /

47User-agent: Amazonbot

48Disallow: /

49Allow: /feed/amazon-rss

51# Global

52User-agent: *

53Disallow: /cgi-bin/

54Disallow: /wp/wp-admin/

55Disallow: /wp/wp-includes/

56Disallow: /wp/wp-content/

57Disallow: /wp-content/plugins/

58Disallow: /wp-content/mu_plugins/

59Disallow: /wp-content/cache/

60Disallow: /wp-content/themes/

61Disallow: /trackback/

62Disallow: /comments/

63Disallow: /category/*/*

64Disallow: */trackback/

65Disallow: */comments/

66Disallow: /search

67Disallow: */*comments=

68Disallow: */*comments-page=

69Disallow: /services/*

70Disallow: /com.condenast/yv8*

72# Xenforo

73Disallow: /civis/account/

74Disallow: /civis/members/

75Disallow: /civis/attachments/

76Disallow: /civis/goto/

77Disallow: /civis/help/

78Disallow: /civis/posts/

79Disallow: /civis/login/

80Disallow: /civis/search/

81Disallow: /civis/admin.php

82Disallow: /civis/threads/*in_iframe=1*

83Disallow: /civis/threads/*wp_data=*

84Disallow: */toggle-*.json?

What do the bots actually get?

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

History

19 October 2026: first checked.

Questions

Does arstechnica.com block GPTBot?

No. arstechnica.com’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 arstechnica.com block ClaudeBot?

Yes. arstechnica.com’s robots.txt disallows ClaudeBot from the whole site (line 45: Disallow: /). ClaudeBot is Anthropic’s crawler for training data. Checked 9 November 2026.

Does arstechnica.com block Google-Extended?

Yes. arstechnica.com’s robots.txt disallows Google-Extended from the whole site (line 45: Disallow: /). 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 arstechnica.com block PerplexityBot?

Yes. arstechnica.com’s robots.txt disallows PerplexityBot from the whole site (line 45: Disallow: /). PerplexityBot is the crawler that indexes pages for Perplexity’s answers. Checked 9 November 2026.

Can ChatGPT search find arstechnica.com?

Yes. arstechnica.com’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.