Does caltech.edu block AI crawlers?

No. caltech.edu’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.caltech.edu/robots.txt · 13 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	line 12 · `Allow: ` under `User-agent: `
`Bingbot`	Microsoft	Allowed	line 12 · `Allow: ` under `User-agent: `
`DuckDuckBot`	DuckDuckGo	Allowed	line 12 · `Allow: ` under `User-agent: `
`Applebot`	Apple	Allowed	line 12 · `Allow: ` under `User-agent: `
`PetalBot`	Huawei	Allowed	line 12 · `Allow: ` under `User-agent: `
`YandexBot`	Yandex	Allowed	line 12 · `Allow: ` under `User-agent: `
`Baiduspider`	Baidu	Allowed	line 12 · `Allow: ` under `User-agent: `

AI search

Bot	Operator	robots.txt	Deciding line
`OAI-SearchBot`	OpenAI	Allowed	line 12 · `Allow: ` under `User-agent: `
`PerplexityBot`	Perplexity	Allowed	line 12 · `Allow: ` under `User-agent: `
`Claude-SearchBot`	Anthropic	Allowed	line 12 · `Allow: ` under `User-agent: `
`DuckAssistBot`	DuckDuckGo	Allowed	line 12 · `Allow: ` under `User-agent: `
`Amazonbot`	Amazon	Allowed	line 12 · `Allow: ` under `User-agent: `
`YouBot`	You.com	Allowed	line 12 · `Allow: ` under `User-agent: `

AI training

Bot	Operator	robots.txt	Deciding line
`GPTBot`	OpenAI	Allowed	line 12 · `Allow: ` under `User-agent: `
`ClaudeBot`	Anthropic	Allowed	line 12 · `Allow: ` under `User-agent: `
`Google-Extended`	Google	Allowed	line 12 · `Allow: ` under `User-agent: `
`CCBot`	Common Crawl	Allowed	line 12 · `Allow: ` under `User-agent: `
`Applebot-Extended`	Apple	Allowed	line 12 · `Allow: ` under `User-agent: `
`GoogleOther`	Google	Allowed	line 12 · `Allow: ` under `User-agent: `
`Meta-ExternalAgent`	Meta	Allowed	line 12 · `Allow: ` under `User-agent: `
`Bytespider`	ByteDance	Allowed	line 12 · `Allow: ` under `User-agent: `

User-triggered fetchers

Bot	Operator	robots.txt	Deciding line
`ChatGPT-User`	OpenAI	Allowed	line 12 · `Allow: ` under `User-agent: `
`Claude-User`	Anthropic	Allowed	line 12 · `Allow: ` under `User-agent: `
`Perplexity-User`	Perplexity	Allowed	line 12 · `Allow: ` under `User-agent: `
`MistralAI-User`	Mistral	Allowed	line 12 · `Allow: ` under `User-agent: `
`Meta-ExternalFetcher`	Meta	Allowed	line 12 · `Allow: ` under `User-agent: `

SEO tools

Bot	Operator	robots.txt	Deciding line
`AhrefsBot`	Ahrefs	Allowed	line 12 · `Allow: ` under `User-agent: `
`SemrushBot`	Semrush	Blocked	line 2 · `Disallow: /` under `User-agent: SemrushBot`
`MJ12bot`	Majestic	Allowed	line 12 · `Allow: ` under `User-agent: `
`DotBot`	Moz	Allowed	line 12 · `Allow: ` under `User-agent: `

View www.caltech.edu/robots.txt · 13 lines

1User-agent: SemrushBot

2Disallow: /

4User-agent: BLP_bbot

5Disallow: /

7User-agent: *

8Disallow: /campus-life-events/calendar/minicalendar/*

9Disallow: /map/landmark_ajax/*

10Disallow: /map/milestone/*

11Crawl-delay: 10

12Allow: *

13Sitemap: https://www.caltech.edu/sitemap.xml

What do the bots actually get?

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

History

19 October 2026: first checked.

Questions

Does caltech.edu block GPTBot?

No. caltech.edu’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 caltech.edu block ClaudeBot?

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

Does caltech.edu block Google-Extended?

No. caltech.edu’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 caltech.edu block PerplexityBot?

No. caltech.edu’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 caltech.edu?

Yes. caltech.edu’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.