Before a search engine crawls a single page of your site, it checks one small text file for permission — robots.txt. This tool generates a properly formatted robots.txt file to control exactly what crawlers can and can't access.
A voluntary protocol that predates Google itself
The Robots Exclusion Protocol, which robots.txt implements, was proposed by Dutch software engineer Martijn Koster in 1994 — years before Google existed — in direct response to early, poorly behaved web crawlers that were overwhelming some sites' servers with excessive requests. The protocol was never formally standardized by any official web standards body for its first 25+ years of existence, relying instead purely on informal, voluntary industry consensus among crawler operators to respect it, until Google finally proposed and helped establish it as an official IETF internet standard (RFC 9309) in 2022 — a genuinely unusual path to formal standardization for such a foundational, widely used piece of web infrastructure.
What this tool generates
The tool creates a properly formatted robots.txt file specifying which crawlers (all, or specific named bots) are allowed or disallowed from accessing particular paths on your site, along with an optional sitemap reference pointing crawlers to your sitemap.xml file — all following the correct syntax that compliant crawlers, including all major search engines, are built to parse and respect.
Where a robots.txt file is genuinely necessary
- Preventing crawlers from indexing non-public or low-value pages — blocking search engines from crawling admin panels, internal search result pages, or duplicate content that shouldn't appear in search results.
- Managing crawl budget for large sites — for very large websites, directing crawlers away from low-priority sections helps ensure limited crawling resources are spent on your most important, valuable pages.
- Pointing crawlers to your sitemap — the sitemap directive within robots.txt is one of the standard ways search engines discover where your sitemap.xml file is located.
- Blocking specific bots while allowing others — some site owners want to allow major search engines to crawl while blocking certain other automated bots, like some AI training crawlers, achievable through robots.txt's per-bot rules.
Frequently asked questions
Does robots.txt actually prevent a page from being indexed? Not necessarily, and this is a genuinely common misunderstanding — robots.txt controls crawling (whether a bot fetches a page's content), but a page can still sometimes appear in search results (typically without a description) if other pages link to it, even if a crawler was blocked from directly accessing it; the meta robots "noindex" tag is the more reliable way to prevent indexing specifically.
Is robots.txt legally binding on crawlers? No — it's a voluntary protocol, and while every major, reputable search engine crawler respects it, robots.txt itself provides no technical enforcement mechanism preventing a non-compliant or malicious bot from ignoring it entirely; it functions on cooperative industry convention, not technical access control.
Where does the robots.txt file need to be located? Always at the root of your domain (like example.com/robots.txt) — crawlers specifically check this exact standard location and won't look for the file anywhere else, making correct placement essential for the file to have any effect at all.
Further reading
RFC 9309 — Robots Exclusion Protocol — The 2022 formal internet standard for robots.txt, decades after the protocol's original 1994 introduction.
Google Search Central — Robots.txt introduction — Google's practical guidance on how its crawlers interpret robots.txt directives.