What Is Robots.txt, and Why Is It Important For SEO?
What is a robots.txt file?
Robots.txt is a standard file used by websites to communicate with web robots and search engine crawlers. It is a plain text file that resides in the root directory of a website and contains instructions for robots about which pages or sections of a website should or should not be crawled and indexed by search engines.
Thus, the robots.txt file is used to control the behavior of web crawlers and prevent them from accessing certain areas of a website, such as login pages, private content, or other sensitive data, and can also specify the crawl delay, which controls the rate at which crawlers can access the site. This can help protect the website from potential security risks, reduce server load, and improve the overall performance of the site.
It's important to note, however, that not all web robots and search engines adhere to the instructions in the robots.txt file, so it should not be relied upon as a security measure.
Some popular tools to test a robots.txt
- Google's Robots Testing Tool: This tool is part of the Google Search Console and allows you to test how Google's crawler will interpret a website's robots.txt file.
- Bing Webmaster Tools: This tool provides a robots.txt tester that allows you to check if a website's robots.txt file is correctly configured for Bing's crawler.
- Yandex Webmaster: Will test your robots.txt file against the URL you entered and report any errors or issues. You can also use Yandex Webmaster to see which pages are blocked by your robots.txt file and adjust the file accordingly.
- SEO Review Tools Robots.txt Checker: This online tool allows you to check a website's robots.txt file and highlights any errors or warnings in the file.
- Varvy SEO Tool: This tool includes a robots.txt tester that allows you to check a website's robots.txt file and see how it will affect search engine crawling.
By using these tools, you can ensure that your website's robots.txt file is properly configured and is allowing search engine crawlers to access the content that you want them to index.
You can read the article "How to Test a Robots.txt File?"
How does a robots.txt file work?
When a web robot or search engine crawler visits a website, it looks for a robots.txt file in the root directory of the site. If a robots.txt file is found, the robot reads the file to determine which pages or sections of the site it is allowed to crawl and index, and which ones it should ignore.
The Robots Exclusion Protocol includes several directives that can be used to control the behavior of web robots and search engine crawlers.
The robots.txt file contains one or more directives, which are instructions that tell robots which pages or sections of a website to crawl or not to crawl. The most common directives are:
- User-agent: specifies which robot the following directives apply to.
- Disallow: specifies which pages or sections of a website should not be crawled and indexed.
- Allow: specifies which pages or sections of a website can be crawled or indexed, even if they are part of a larger section that has been disallowed.
- Crawl-delay: specifies the number of seconds that a robot should wait between requests when crawling a website. Note that some robots ignore this directive.
- "Sitemap": This directive is used to specify the location of the website's sitemap file, which contains a list of all the pages on the website that should be crawled and indexed by search engines.
For example, a robots.txt file might include the following directives:
Disallow: /admin/
Disallow: /*search/
Allow: /search/news/$
Crawl-delay: 15
Sitemap: https://example.com/sitemap.xml
In this example, the "User-agent: *" directive applies to all web robots and search engine crawlers. The "Disallow: /admin/" directive tells the robots not to crawl any pages that beginning "/admin/" in the URL, such as pages for site administrators. The "Disallow: /*search/" directive tells the robots not to crawl any pages that contain "search/" in the URL, such as site search results. The "Allow: /search/news/$" directive allows the bots to crawl the "/search/news/" page. The "Crawl-delay: 15" directive specifies a crawl delay of 15 seconds between requests to reduce server load and improve the overall performance of the website.
You can read the article "What Directives are Used in the Robots Exclusion Protocol?"
How does the robots.txt file affect SEO?
The robots.txt file can affect SEO (Search Engine Optimization) in a number of ways:
- Indexing: By using the robots.txt file, you can control which pages of your website are indexed by search engines. This can be helpful for ensuring that only the most important pages of your website appear in search results, while keeping less important or duplicate content out of the search results.
- Crawl budget: Search engines have a finite amount of resources they can use to crawl and index websites. By using the robots.txt file to block low-quality or irrelevant pages, you can help ensure that search engines focus their crawling efforts on the most important pages of your website, which can help improve the overall crawling and indexing efficiency of your website.
- Duplicate content: If you have multiple versions of the same content on your website (e.g. both a www and non-www version), search engines may view these as duplicate content. By using the robots.txt file to block one of these versions, you can help prevent duplicate content issues that could negatively impact your SEO.
Note. It is recommended to set up a 301 redirect from one version of the site to another - Server load: By blocking search engine crawlers from accessing certain pages or directories, you can help reduce the load on your server. This can be helpful if you have a large website or if you're experiencing performance issues.
- Security: While the robots.txt file is not a security measure, it can be used to block access to certain pages or directories that should not be publicly accessible. This can help prevent unauthorized access to sensitive information or pages.
It's important to note that the robots.txt file should be used judiciously and with a clear understanding of its potential impact on your website's SEO. Blocking too many pages or directories could result in reduced visibility in search results, while failing to block certain pages could result in duplicate content issues or other SEO problems.
You can read the article "What are the Problems When Using Robots.txt?"
You can read the article "How to Adjust Website Crawl Rate for Different Search Engines?"