What is website indexability? In a nutshell, indexability means the efficiency in how Internet search engine robots, spiders, crawlers, worms, and/or ants are able to read the web pages for a website and determine their rank in the list of search results that they return to a user. One way to do this is with the addition of a robots.txt file. Add the file to the root of the website to instruct an SEO (Search Engine Optimization) robot which pages to index. This will make sure that only the most relevant pages are indexed.
Not all SEO robots will read a robots.txt file. Most malware crawlers will unfortunately ignore it as their purpose is malicious. They do not care if they are only allowed access to certain pages. The main purpose of the robots.txt file is to tell friendly SEO crawlers which pages they should ignore while indexing the site. This is helpful in the case of an infinite domain space. An example of an infinite domain namespace might be one where users upload files into an online document repository. These documents are considered to be media and not content so the webmaster should add a line to the robots.txt file to disallow access to the root URL for this document repository. The more results returned from a site with the same URL will often degrade the result ranking of a page.
Test pages are another example of parts of a website that should be passed over. Also any content not meant for visitors. This could include web pages that have been added to the site in order to calibrate the appearance of the pages but are not ready to be shared. Pages that can’t be accessed directly by a user conducting a search undermines the credibility of the results and will thus begin to degrade the page ranking.
In order to increase website indexability, the robots.txt file can also be used to provide instructions to specific SEO robots. Different algorithms are used by the search engines to index web pages. For example, one set of pages may need to be restricted for one search engine while allowing access to another. Lines can be added to the robots.txt file that gives specific instructions by including the name of certain search engines such as Google, Yahoo!, and Bing. This could actually be very important in determining the rank of your pages for specific keywords, depending on the rules and methods used by the search agent.
The purpose of a robots.txt file is to convey important information to visiting SEO robots or crawlers about how they should proceed in indexing a website. The main purpose of the file is to keep the lesser pages from being indexed to the more pertinent pages are. Another important function is to communicate instructions to specific robots on how to proceed while indexing the website. This insures that the most important pages are indexed, which will hopefully increase page rankings.