What is robots.txt file and how does it work?
Learn what a robots.txt file does, when to use it, common mistakes, and best practices for controlling search engine crawling.
A robots.txt file is a text file placed at the root of a website that tells search engine crawlers which pages or sections they can access.
What is robots.txt file?
A robots.txt generator creates a valid `robots.txt` file that tells crawlers (Google, Bing, and other bots) which URLs they're allowed to crawl. It's one of the first files search engines look for on your domain, and it helps prevent wasted crawl budget on admin or duplicate routes. Instead of manually writing directives and risking mistakes, you pick a policy, add allow/disallow paths, and download a ready-to-deploy file.
In practice, robots.txt file depends on consistent formatting, predictable URLs, and accurate values so search engines and browsers interpret your intent correctly.
Why robots.txt file matters for SEO
robots.txt file matters because it reduces ambiguity about how your pages should be discovered, rendered, or shared. Clear signals help search engines crawl efficiently, improve consistency across URLs, and reduce mistakes that can hurt visibility.
Even for non-SEO tools, the output affects user experience, performance, or accessibility. Those signals influence rankings through engagement and crawlability over time.
How robots.txt file works
robots.txt file works by following a small set of rules that browsers and search engines expect. When those rules are consistent, you get predictable behavior across pages and platforms.
- Choose a policy (allow all, block all, or custom)
- Add any Allow/Disallow paths if using custom rules
- Optionally include your sitemap URL
- Click Generate and download robots.txt
You should use robots.txt file when
- You need to block admin or low-value URLs from crawling
- You want to guide crawlers to your sitemap
- You manage a large or frequently updated site
Examples and use cases
Common scenarios for robots.txt file include the following. These examples help you decide when to apply it and what to check during implementation.
- Blocking admin or private routes from crawlers
- Preventing indexing of staging environments
- Pointing crawlers to your sitemap.xml
- Reducing crawl noise from search/filter parameter URLs
- Blocking internal preview routes or tool UIs from indexing
Common mistakes
Most issues come from inconsistent configuration or skipping validation. Avoid the mistakes below to keep results predictable across pages.
- Blocking the entire site with Disallow: /
- Blocking CSS or JS needed for rendering
- Using robots.txt instead of noindex for removal
FAQs
Does robots.txt hide pages from the internet?
No. robots.txt is a set of crawl instructions for compliant bots. It does not enforce access control—use authentication for private content. In most cases, the safest approach is to validate your robots.txt file setup and check results before shipping.
Should I include a Sitemap line in robots.txt?
Usually yes. Adding a Sitemap directive helps crawlers discover your sitemap faster, especially on new sites. In most cases, the safest approach is to validate your robots.txt file setup and check results before shipping.
What does Disallow: / do?
It tells crawlers not to crawl any paths on your site for the specified user-agent. It's commonly used for staging or private sites. In most cases, the safest approach is to validate your robots.txt file setup and check results before shipping.
Is robots.txt the same as noindex?
No. robots.txt controls crawling. noindex is a directive (usually via meta robots) that controls indexing. If you block a page in robots.txt, Google may not crawl it and therefore may not see a noindex tag on that page. In most cases, the safest approach is to validate your robots.txt file setup and check results before shipping.
Should I block /api or /_next?
Generally you don't need to block Next.js internal assets if they're not indexable pages. Focus on blocking sensitive/admin areas and low-value or duplicate content routes. In most cases, the safest approach is to validate your robots.txt file setup and check results before shipping.
Do I need robots.txt file?
You need robots.txt file when it impacts how your site is crawled, rendered, or shared. If robots.txt file affects discovery, performance, or compliance, setting it correctly reduces future fixes and makes auditing easier. In most cases, the safest approach is to validate your robots.txt file setup and check results before shipping.
Related resources
These links help you connect related SEO setup tasks and keep your implementation consistent.