What is robots.txt file?

A robots.txt file is a simple text file that is placed on a website’s server to instruct search engine crawlers on how to interact with the website’s pages. It is an important tool for webmasters to manage which parts of their site should be scanned and indexed by search engines. 

In this article, let’s delve into the details of a robots.txt file, its purpose, importance for SEO, how to create and implement it, as well as its limitations.

Understanding robots.txt file

A robots.txt file is a file that is placed in the root directory of a website, indicating to web crawlers which pages or directories they are allowed or disallowed to crawl. It serves as a guide for search engine robots on how to navigate a website. By specifying directives in the robots.txt file, webmasters can control the access of search engine crawlers to different parts of their site.

A robots.txt acts as a gatekeeper, helping to prevent sensitive or irrelevant pages from being indexed, while ensuring that important pages are discovered by search engines.

Imagine a scenario where a website contains certain pages that are not meant for public viewing, such as administrative pages or private user profiles. In such cases, webmasters can use the robots.txt file to explicitly instruct search engine crawlers to avoid accessing these pages. This ensures that sensitive information remains hidden from search engine results, protecting the privacy and security of the website and its users.

When should you use a robots.txt file?

A robots.txt file is used to guide web robots on how to crawl pages on a website. Here are situations when you might want to use a robots.txt file:

1. Preventing Crawl of Duplicate Content: If your site has pages with duplicate content that you don’t want search engines to index, you can use a robots.txt file to prevent them from crawling these pages.
2. Preserving Crawl Budget: For large websites, using a robots.txt can help save your site’s crawl budget (the number of times a search engine will crawl your site within a certain timeframe) by preventing search engines from crawling irrelevant or low-value pages.
3. Securing Sensitive Information: If there are sections of your site that contain sensitive information, you can use a robots.txt file to block bots from accessing these areas. However, this should not be your only line of defence as some bots do not respect the instructions in robots.txt files.
4. Blocking Internal Search Result Pages: If your site has a search feature, you may want to block search result pages from being crawled to prevent them from appearing in search engine results.
5. Exclude Testing or Staging Environments: If you have testing or staging environments that should not be indexed by search engines, use robots.txt to block access to these areas.
6. Preventing Indexing of Certain Files and Directories: You may want to prevent the indexing of certain directories, images or PDF files on your site. A robots.txt file can be used to disallow crawling of these resources.

Remember, a robots.txt file doesn’t guarantee that a page won’t be indexed – it simply requests that bots do not crawl it. To ensure a page isn’t indexed, you’ll need to use other methods like password protection or the noindex meta tag.

What should be in robots.txt file?

A robots.txt file should include directives that inform web crawlers which areas of your website they are allowed or not allowed to scan and index. Here’s a basic structure of what a robots.txt file might look like:

User-agent: *
Disallow: /wp-admin/
Allow: /wp-admin/themes/mytheme
Crawl-Delay: 10
Sitemap: https://www.example.com/sitemap.xml
# This is a comment

User-agent Directive

The User-agent directive specifies which web crawler or user agent the following rules apply to. An asterisk (*) is a wildcard that matches all user agents. This is the default rule for all web crawlers.

Disallow Directive

The Disallow directive tells web crawlers which parts of your website should not be crawled or indexed. In this example, /wp-admin/ is a page that web crawlers are not allowed to access. You can specify multiple Disallow directives for different directories or paths you want to block.

Allow Directive

The Allow directive is used to override a more general Disallow directive. It specifies that a specific directory or page is allowed to be crawled even if there’s a broader “Disallow” rule in place. In this case, /wp-admin/themes/mytheme is explicitly allowed.

Crawl-Delay Directive (Optional)

The Crawl-Delay directive is optional and specifies the delay, in seconds, between consecutive requests made by web crawlers to your site. It helps prevent overloading your server, especially if you have a large website. In this example, there’s a 10-second delay between requests for all user agents.

Keep in mind that not all web crawlers (such as Google) support the Crawl-Delay directive, and even those that do may interpret it differently. It is particularly relevant for larger websites with substantial traffic or limited server resources where controlling the crawl rate is essential to ensure that the website remains responsive and accessible to visitors.

Sitemap Directive

The Sitemap directive provides the URL of your XML sitemap. This helps search engines discover and index your pages more efficiently. Include the full URL to your sitemap file. In this case, it points to https://www.example.com/sitemap.xml.

Comments in Robots.txt (# This is a comment)

Comments are not directives but can be added to your robots.txt file to provide explanations for the rules. Comments start with a “#” symbol and are ignored by web crawlers. They are useful for documenting the purpose of your rules, making your robots.txt file more readable, and providing context for other website administrators.

Best Practices in Using Robots.txt

Creating and implementing a robots.txt file is a straightforward process that involves understanding the guidelines and avoiding common mistakes. 

To create an effective robots.txt file, you need to consider best practices to ensure that the instructions provided are clear and organized in a logical way:

• Use lowercase for all directives: Keep all directives in lowercase as search engines are case-sensitive.
• Place robots.txt in the Root Directory: Place your robots.txt file in the root directory of your website, typically located at https://www.example.com/robots.txt.
• Allow all Search Engine Crawlers by Default: To permit access to all web crawlers by default, use the “*” wildcard in place of specific user-agent strings.
• Use “Disallow” to exclude sections: Utilize the “Disallow” statement to accurately exclude specific sections of the website. Be precise to avoid unintentionally blocking crucial content.
• Regularly test uour Robots.txt File: Consistently test your robots.txt file with tools like Google’s robots.txt tester to verify that it precisely targets the intended directories or files and functions correctly.
• Keep your Robots.txt File up-to-date: Ensure your robots.txt file remains current. As your website evolves, adjust the rules as necessary to accommodate changes.
• Provide sitemap information: Enhance search engine indexing efficiency by including a “Sitemap” directive that points to your XML sitemap.
• Avoid hiding sensitive information with robots.txt: Do not use robots.txt to conceal sensitive data. Instead, employ HTTP authentication or other security measures for protection.
• Use comments for clarity: Enhance readability and provide context by adding comments to explain the purpose of your rules within the robots.txt file.
• Monitor crawl Behaviour: Regularly monitor your website’s crawl behaviour through tools like Google Search Console to confirm that search engines are adhering to your robots.txt directives.

By following these best practices, you can effectively manage web crawler access to your website, protect sensitive information, and ensure that search engines index your content properly.

Conclusion

Understanding the basics of a robots.txt file is essential for webmasters who want to optimize their website’s visibility in search engine results. 

By correctly configuring and regularly updating this simple file, webmasters can control how search engines access and index their site, ensuring that only relevant and valuable content is displayed to users. 

Remember to follow the guidelines, avoid common mistakes, and consider the limitations and alternatives to maximise the benefits of a robots.txt file for SEO.

FAQs about robots.txt