How to Configure Robots.txt in Magento 2

As you know, configuring robot.txt is important to any website that is working on a site’s SEO. Particularly, when you configure the sitemap to allow search engines to index your store, it is necessary to give web crawlers the instructions in the robot.txt file to avoid indexing the disallowed sites. The robot.txt file, that resides in the root of your Magento installation, is directive that search engines such as Google, Yahoo, Bing can recognize and track easily. In this post, I will introduce the guides to configure the robot.txt file so that it works well with your site.

Follow the simple guide here to configure robots.txt:

• On the Admin panel, click Stores. In the Settings section, select Configuration.
• Select Design under General in the panel on the left
• Open the Search Engine Robots section, and continue with following:

• In Default Robots, select one of the following:
  • INDEX, FOLLOW
  • NOINDEX, FOLLOW
  • INDEX, NOFOLLOW
  • NOINDEX, NOFOLLOW
• In the Edit Custom instruction of robots.txt File field, enter custom instructions if needed.

• In the Reset to Defaults field, click on Reset to Default button if need to restore the default instructions.

• When complete, click Save Config.

Examples of Custom Instructions

• Allows Full Access

User-agent:*
Disallow:

• Disallows Access to All Folders

User-agent:*
Disallow: 

• Default Instructions

Disallow: /lib/
Disallow: /*.php$
Disallow: /pkginfo/
Disallow: /report/
Disallow: /var/
Disallow: /catalog/
Disallow: /customer/
Disallow: /sendfriend/
Disallow: /review/
Disallow: /*SID=

Ref: Magento 2 User Guide