Agent Web Index › cornelsen.de
Can AI assistants read cornelsen.de?
Measured on 2026-09-15 by asking the site 5 times — once as a browser, once as each of the 4 crawlers that feed ChatGPT, Claude, Perplexity, Gemini, Meta AI, Apple Intelligence and Doubao — and comparing what came back. The AI-training opt-out tokens that never crawl are read from robots.txt instead. Tranco rank #10,532.
B76 / 100
2 of 4 crawlers can read this page.
More readable than 55% of the 47,934 sites measured so far.
Structured data: BreadcrumbList, WebSite, Organization.
What each crawler got back
| Crawler | HTTP | Result | robots.txt |
|---|---|---|---|
| ClaudeBot (Claude) | 200 | can read it | allowed-by-star |
| GPTBot (ChatGPT) | 503 | challenged | blocked |
| OAI-SearchBot (ChatGPT Search) | 200 | can read it | allowed-by-star |
| PerplexityBot (Perplexity) | 503 | challenged | allowed-by-star |
| Google-Extended (Gemini, AI Overviews) a robots.txt token, not a crawler: it controls how already-crawled pages may be used, and never makes a request of its own | — | not opted out | allowed-by-star |
What to change, in order
- Let in the 1 crawler your own robots.txt already allows+1 crawlerPerplexityBot is turned away before reading the page (served a bot challenge instead of the page), while robots.txt permits it — so this block is not written in your site. No CDN signature was found in the response headers, so the refusal comes from the origin server itself or from a WAF this index does not recognise. Fixing it takes this domain from 2 to 3 of 4 crawlers.
- Publish llms.txtllms.txt is missing, so an assistant has to discover the site by following links. llms.txt is the emerging convention for telling an assistant which pages actually matter.
- 1 crawler is named and refused in robots.txt — a deliberate choiceGPTBot is blocked by a rule that names it. Nothing to fix here: this page records what is true, not what should be. It is listed so the deliberate part of the block is not confused with the accidental part above.
Get told if this changes
One email only when a measured crawler flips on cornelsen.de, served to refused or back. No schedule, no newsletter; double opt-in, one-click stop.
The checks
- Answers AI agents like it answers people60%
- Readable without JavaScript100%
- robots.txt lets the crawlers in80%
- Facts in JSON-LD100%
- Content reachable, not buried46%
- Publishes a map of itself45%
- Plain structure97%
History
2026-09-13: 71 · 2026-09-15: 76
Full AI-visibility report for cornelsen.de → Scan your own site →Sites with a similar score
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<a href="https://aivis.lumnika.com/ai-readiness/cornelsen.de"><img src="https://aivis.lumnika.com/ai-readiness/cornelsen.de/badge.svg" alt="AI readability"></a>
Method. 5 live HTTP requests (one per crawler, one as a browser) plus robots.txt, llms.txt, sitemap.xml and security.txt, 12-second timeout each,
from a single vantage point. Blocking AI crawlers is a legitimate choice, not a failure: this page records what is true, not what should be.
Domain comes from the Tranco research list. One page per domain — the homepage — is audited.
Part of the Agent Web Index, 47,934 domains measured, updated continuously.
Part of the Agent Web Index, 47,934 domains measured, updated continuously.