Common Robots.txt Mistakes That Can Harm Your SEO

Common robots.txt mistakes that can harm your SEO include:

• Blocking the entire website by using Disallow: / for all user agents, which prevents search engines from indexing any pages, causing your site to disappear from search results.

• Blocking important resources like CSS and JavaScript files, especially in WordPress sites (e.g., blocking /wp-includes/ or /wp-content/), which can make Google think your site is broken or not mobile-friendly.

• Disallowing URLs that should rank, such as product or service pages mistakenly blocked due to perceived duplication, leading to loss of valuable pages from search results.

• Using Noindex directives in robots.txt, which Google no longer supports since 2019; this means pages blocked this way may still appear in search results.

• Not including the sitemap URL in robots.txt, which makes it harder for search engines to discover and crawl your sitemap efficiently, potentially delaying indexing and harming rankings.

• Incorrect use of trailing slashes in disallow rules, which can cause unintended blocking of entire directories instead of specific URLs.

• Using conflicting or redundant rules, such as simultaneously allowing and disallowing the same path, which confuses crawlers and leads to unpredictable indexing behaviour.

• Failing to update robots.txt after development, where a file blocking all bots is accidentally left on the live site, preventing indexing of the production website.

• Using default CMS robots.txt files without customization, which may be overly restrictive or not suited to your site’s structure.

To avoid these issues, ensure your robots.txt is carefully crafted and tested, includes a sitemap reference, allows essential resources, and blocks only truly non-public or duplicate content pages. Tools exist to validate your robots.txt rules and simulate crawler behaviour to prevent SEO damage.