Robots.txt Validator

The robots.txt file is a simple text file placed at the root of a website (e.g., example.com/robots.txt) that tells web crawlers which pages or sections they are allowed or not allowed to access. It follows the Robots Exclusion Protocol, a standard used by all major search engines including Google, Bing, and others. A robots.txt file consists of one or more groups, each starting with a User-agent directive that specifies which crawler the rules apply to. The wildcard (*) matches all crawlers. Within each group, Allow and Disallow directives control access to specific URL paths. The Sitemap directive can appear anywhere in the file and points crawlers to your XML sitemap. Common use cases for robots.txt include blocking crawlers from admin panels, duplicate content, staging environments, and resource-heavy pages that don't need indexing. It's important to note that robots.txt is advisory — well-behaved crawlers follow it, but malicious bots may ignore it entirely. For truly private content, use authentication or server-side access controls instead. This validator checks your robots.txt for syntax errors such as missing colons, unknown directives, and rules that appear before any User-agent declaration. It also warns about best-practice issues like non-absolute sitemap URLs and paths that don't start with a forward slash. The built-in URL tester lets you simulate how a specific crawler would treat a given path based on your rules. Tips for writing a good robots.txt: always include a User-agent line before any Allow/Disallow rules, use absolute URLs for Sitemap directives, and test your rules before deploying to avoid accidentally blocking important pages from search engines.