Who blocks AI · #428 in the Majestic Million

robots.txt · checked 9 Nov 2026

Does scientificamerican.com block AI crawlers?

Yes. scientificamerican.com’s robots.txt blocks 9 of the 19 AI crawlers we track, including GPTBot, ClaudeBot, Google-Extended and 6 more. Search engines such as Googlebot and Bingbot may crawl it.

GPTBotBlocked OAI-SearchBotBlocked ClaudeBotBlocked PerplexityBotBlocked Google-ExtendedBlocked CCBotBlocked

robots.txt: www.scientificamerican.com/robots.txt · 37 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	Blocked	line 31 · `Disallow: /` under `User-agent: OAI-SearchBot`
`PerplexityBot`	Perplexity	Blocked	line 31 · `Disallow: /` under `User-agent: PerplexityBot`
`Claude-SearchBot`	Anthropic	Blocked	line 31 · `Disallow: /` under `User-agent: Claude-SearchBot`
`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	Blocked	line 31 · `Disallow: /` under `User-agent: GPTBot`
`ClaudeBot`	Anthropic	Blocked	line 31 · `Disallow: /` under `User-agent: ClaudeBot`
`Google-Extended`	Google	Blocked	line 31 · `Disallow: /` under `User-agent: Google-Extended`
`CCBot`	Common Crawl	Blocked	line 31 · `Disallow: /` under `User-agent: CCBot`
`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	Blocked	line 31 · `Disallow: /` under `User-agent: ChatGPT-User`
`Claude-User`	Anthropic	Blocked	line 31 · `Disallow: /` under `User-agent: Claude-User`
`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.scientificamerican.com/robots.txt · 37 lines

1User-agent: 008

2Disallow: /

4User-agent: *

5Sitemap: https://www.scientificamerican.com/platform/syndication/sitemaps/

7Crawl-Delay: 5

8Disallow: /admin/

9Disallow: /checkout

10Disallow: /upgrade-offer/

11Disallow: /platform/customercare/

12Disallow: /preview/

15User-agent: CCBot

16User-agent: GPTBot

17User-agent: ChatGPT-User

18User-agent: OAI-SearchBot

19User-agent: anthropic-ai

20User-agent: ClaudeBot

21User-agent: Claude-User

22User-agent: Claude-SearchBot

23User-agent: cohere-ai

24User-agent: Google-Extended

25User-agent: PerplexityBot

26User-agent: RepoLookupBot

27User-agent: AwarioSmartBot

28User-agent: PerplexityAI

29Allow: /travel/

30Allow: /getsciam/

31Disallow: /

34# Draft spec

35User-Agent: __usage_ai-training

36Disallow: /

What do the bots actually get?

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

History

19 October 2026: first checked.

Questions

Does scientificamerican.com block GPTBot?

Yes. scientificamerican.com’s robots.txt disallows GPTBot from the whole site (line 31: Disallow: /). GPTBot is OpenAI’s crawler for training data; blocking it doesn’t affect ChatGPT search, which uses OAI-SearchBot. Checked 9 November 2026.

Does scientificamerican.com block ClaudeBot?

Yes. scientificamerican.com’s robots.txt disallows ClaudeBot from the whole site (line 31: Disallow: /). ClaudeBot is Anthropic’s crawler for training data. Checked 9 November 2026.

Does scientificamerican.com block Google-Extended?

Yes. scientificamerican.com’s robots.txt disallows Google-Extended from the whole site (line 31: 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 scientificamerican.com block PerplexityBot?

Yes. scientificamerican.com’s robots.txt disallows PerplexityBot from the whole site (line 31: Disallow: /). PerplexityBot is the crawler that indexes pages for Perplexity’s answers. Checked 9 November 2026.

Can ChatGPT search find scientificamerican.com?

Not through its own crawler. scientificamerican.com’s robots.txt disallows OAI-SearchBot from the whole site (line 31: Disallow: /). OAI-SearchBot is the crawler behind ChatGPT search; blocking it keeps the site out of ChatGPT’s search answers. Checked 9 November 2026.