Quick answer

robots.txt blocks crawling, not indexing.

robots.txt vs noindex

robots.txt blocks crawling, not indexing. Use noindex meta or header to prevent indexing.

Common causes

How to fix

FAQ

Disallow removes from index?
No; blocks crawl.
How prevent index?
noindex meta or header.

Fix it now

Try in validator (prefill this example)

Related

All tools · Canonical