How do I make an internal link with CKEditor? I am using Drupal 8.

Using the standard WYSIWYG editor, when I click on the link button, I only get the option to add a url. I would have thought there would be some capabilities to look up existing pages. 

Is there some way to create an internal link?
Yes, what you're looking for is covered by the LinkIt project.


  Linkit provides an easy interface for internal and external linking
  with wysiwyg editors by using an autocomplete field. Linkit has by
  default support for nodes, users, taxonomy terms, files, comments and
  basic support for all types of entities that defines a canonical link
  template.


Once you install the module, you'll need to create a profile (under Administration > Configuration > Content authoring > Linkit) for selecting your entities. Following that, configure your text format (under Administration > Configuration > Content authoring > Text formats and editors) to use your LinkIt profile. 

Once associated, you should be able to add a LinkIt button to your text format toolbar which will let you autocomplete links to your page content.