Who blocks AI · #721 in the Majestic Million

robots.txt · checked 9 Nov 2026

Does phys.org block AI crawlers?

No. phys.org’s robots.txt lets all 19 AI crawlers we track crawl the site, though it keeps GPTBot, ClaudeBot and 4 more out of some paths. Search engines such as Googlebot and Bingbot may crawl it.

GPTBotPartly blocked OAI-SearchBotAllowed ClaudeBotPartly blocked PerplexityBotAllowed Google-ExtendedPartly blocked CCBotPartly blocked

robots.txt: phys.org/robots.txt · 72 lines
llms.txt: found
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	line 2 · `Allow: /` under `User-agent: *`
`Bingbot`	Microsoft	Allowed	line 2 · `Allow: /` under `User-agent: *`
`DuckDuckBot`	DuckDuckGo	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Applebot`	Apple	Allowed	line 2 · `Allow: /` under `User-agent: *`
`PetalBot`	Huawei	Allowed	line 2 · `Allow: /` under `User-agent: *`
`YandexBot`	Yandex	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Baiduspider`	Baidu	Allowed	line 2 · `Allow: /` under `User-agent: *`

AI search

Bot	Operator	robots.txt	Deciding line
`OAI-SearchBot`	OpenAI	Allowed	line 2 · `Allow: /` under `User-agent: *`
`PerplexityBot`	Perplexity	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Claude-SearchBot`	Anthropic	Allowed	line 2 · `Allow: /` under `User-agent: *`
`DuckAssistBot`	DuckDuckGo	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Amazonbot`	Amazon	Allowed	line 2 · `Allow: /` under `User-agent: *`
`YouBot`	You.com	Allowed	line 2 · `Allow: /` under `User-agent: *`

AI training

Bot	Operator	robots.txt	Deciding line
`GPTBot`	OpenAI	Partly blocked	line 16 · `Disallow: /news/` line 17 · `Disallow: /partners/` and 2 more
`ClaudeBot`	Anthropic	Partly blocked	line 10 · `Disallow: /news/` line 11 · `Disallow: /partners/` and 2 more
`Google-Extended`	Google	Partly blocked	line 49 · `Disallow: /news/` line 50 · `Disallow: /tags/`
`CCBot`	Common Crawl	Partly blocked	line 31 · `Disallow: /news/` line 32 · `Disallow: /partners/` and 2 more
`Applebot-Extended`	Apple	Partly blocked	line 53 · `Disallow: /news/` line 54 · `Disallow: /tags/`
`GoogleOther`	Google	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Meta-ExternalAgent`	Meta	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Bytespider`	ByteDance	Partly blocked	line 37 · `Disallow: /news/` line 38 · `Disallow: /partners/` and 2 more

User-triggered fetchers

Bot	Operator	robots.txt	Deciding line
`ChatGPT-User`	OpenAI	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Claude-User`	Anthropic	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Perplexity-User`	Perplexity	Allowed	line 2 · `Allow: /` under `User-agent: *`
`MistralAI-User`	Mistral	Allowed	line 2 · `Allow: /` under `User-agent: *`
`Meta-ExternalFetcher`	Meta	Allowed	line 2 · `Allow: /` under `User-agent: *`

SEO tools

Bot	Operator	robots.txt	Deciding line
`AhrefsBot`	Ahrefs	Partly blocked	line 28 · `Disallow: /tags/`
`SemrushBot`	Semrush	Allowed	line 2 · `Allow: /` under `User-agent: *`
`MJ12bot`	Majestic	Allowed	line 2 · `Allow: /` under `User-agent: *`
`DotBot`	Moz	Allowed	line 2 · `Allow: /` under `User-agent: *`

View phys.org/robots.txt · 72 lines

1User-agent: *

2Allow: /

3Disallow: /search/

4Disallow: /rss-feed/search/

5Disallow: /rss-feed/breaking/search/

6Disallow: /rss-feed/tags/

7Disallow: /*/sort/

9User-Agent: ClaudeBot

10Disallow: /news/

11Disallow: /partners/

12Disallow: /journals/

13Disallow: /tags/

15User-Agent: GPTBot

16Disallow: /news/

17Disallow: /partners/

18Disallow: /journals/

19Disallow: /tags/

21User-agent: FacebookBot

22Disallow: /news/

23Disallow: /partners/

24Disallow: /journals/

25Disallow: /tags/

27User-agent: AhrefsBot

28Disallow: /tags/

30User-agent: CCbot

31Disallow: /news/

32Disallow: /partners/

33Disallow: /journals/

34Disallow: /tags/

36User-Agent: Bytespider

37Disallow: /news/

38Disallow: /partners/

39Disallow: /journals/

40Disallow: /tags/

42User-Agent: cohere-ai

43Disallow: /news/

44Disallow: /partners/

45Disallow: /journals/

46Disallow: /tags/

48User-agent: Google-Extended

49Disallow: /news/

50Disallow: /tags/

52User-agent: Applebot-Extended

53Disallow: /news/

54Disallow: /tags/

56User-Agent: FriendlyCrawler

57Disallow: /

59User-Agent: ChatGLM-Spider

60Disallow: /

62User-Agent: Scrapy

63Disallow: /

65User-agent: DataForSeoBot

66Disallow: /

68User-Agent: ImagesiftBot

69Disallow: /news/

71Sitemap: https://phys.org/sitemap/indx/

What do the bots actually get?

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

History

19 October 2026: first checked.

Questions

Does phys.org block GPTBot?

Partly. phys.org’s robots.txt keeps GPTBot out of some paths, such as /news/, and lets it crawl the rest. GPTBot is OpenAI’s crawler for training data; blocking it doesn’t affect ChatGPT search, which uses OAI-SearchBot. Checked 9 November 2026.

Does phys.org block ClaudeBot?

Partly. phys.org’s robots.txt keeps ClaudeBot out of some paths, such as /news/, and lets it crawl the rest. ClaudeBot is Anthropic’s crawler for training data. Checked 9 November 2026.

Does phys.org block Google-Extended?

Partly. phys.org’s robots.txt keeps Google-Extended out of some paths, such as /news/, and lets it crawl the rest. 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 phys.org block PerplexityBot?

No. phys.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 phys.org?

Yes. phys.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.