A robots.txt checker helps interpret the instructions a website sends to crawlers. The file does not directly decide which pages can be indexed: it primarily controls crawling. Review it together with meta robots, canonical tags, HTTP status and XML sitemaps.
Robots.txt tester for URLs and crawlers
The same path can be allowed for Googlebot and blocked for another user-agent. The tester selects the most specific group, applies wildcards and end anchors, and evaluates the longest matching allow or disallow rule.
Common robots.txt errors
Groups without a user-agent, malformed directives, overly broad paths and accidental blocks on CSS, JavaScript or strategic sections can restrict crawling. A Disallow rule is not a reliable way to remove a URL from Google.
Sitemaps and related technical checks
Declaring a sitemap in robots.txt helps crawlers discover the XML file. Continue with the sitemap checker and canonical/indexability checker to verify that crawling and indexing signals agree.
Use a robots.txt generator carefully
A robots.txt generator creates valid syntax but cannot know the SEO value of your directories. Before publishing, review templates, private areas, parameters, rendering resources and differences between staging and production.