Robots.txt is a text file placed at the root of a site that tells crawlers (Google, Bing, GPTBot) which pages they may or may not access and index.
The robots.txt file lives at yourdomain.com/robots.txt and contains instructions for web robots (crawlers). Using the "User-agent" directive (identifies the crawler) and "Disallow" or "Allow" (specify what it can access), you can control which sections of the site are accessible. Important: robots.txt does not guarantee that Google will not index blocked pages if there are links to them — use "noindex" to actually prevent indexing. Google recommends allowing GPTBot and ClaudeBot access to benefit from AI visibility.
A misconfigured robots.txt can accidentally block the indexing of an entire site or important sections. It is one of the first checks in any technical SEO audit. At the same time, explicitly allowing AI crawlers (GPTBot, ClaudeBot, PerplexityBot) increases your chances of being cited in AI answers.
Source: Google Search Central — Robots.txtTechnical SEO covers the optimizations of your site's infrastructure — crawlability, indexing, loading speed, HTTPS and data structure — that let Google find and understand your pages.
Crawlability is the ability of Google's robots to access, navigate and read your site's pages — an essential prerequisite for indexing and ranking.
The canonical tag (rel="canonical") tells Google which is the main version of a page when similar or duplicate URLs exist, preventing duplicate-content penalties.
An XML sitemap is a file that lists all the important URLs of your site, helping Google discover and index them faster and more completely.
Explore how to apply this concept to your industry and city.