Marcin Kijak

After installation you can find “Noindex by path” option in the main menu. This allows you to simply add relative paths 
you need to exclude from SERPs. Add a path (including slashes from begging and the end of the string) and save the 
changes. Since this plugin is called to be “simple” you can add only one path at once, but the process is smooth 
and easy.
Plugin will add “noindex” meta tag which is an instruction for search engines that this particular page should not be indexed. 
Technically it modifies wp_head tag.

Noindex by Path

Ask search engines not to index individual pages by a relative path - which means you can set every url no matter it is a page, category listing or an …

radgh

This simple and lightweight plugin adds a “Hide from search engines” checkbox above the publish box to pages. By 
ticking this box, a meta tag will be placed into the <code><head></code> section of your page specifying that robots should 
not index the page.
By default this only applies to pages. You may extend this functionality to posts or other custom post types with a small bit of code. See the FAQ’s tab for further instructions.

Noindex Pages

Ask search engines not to index individual pages by checking an option in the publish post box.

Noindex by Path vs Noindex Pages