Is there a way to make a pure vanila page of just HTML/CSS/JS

I’ve done this in the past by using custom page templates.

Basically, there are two ways to create a custom page template.

  1. You can create a file in your themes directory and name it page-vanilla-html.php.

  2. You can create a file and name it whatever you want (for example vanilla-html.php). You just need to include a template description at the top of the file:

     <?php
     /*
      * Template Name: A Vanilla HTML/CSS/JS Custom Page Template
      * Description: This template is nothing but vanilla HTML/CSS/JS!
      */
     ?>
    

Once you’ve created the custom template, you simply create a new page within WordPress. If the name of the page is “Vanilla HTML” it will search for a file named page-vanilla-html.php and load it automatically. If you used the second method, you can select the template from the drop down on the right side of the page creation screen.