It’s default page template?
It’s very short post. We know, if we need check what template used at some page we can use function is_page_template(). But what to do if we need check default page template that is page.php?
Problem: How to check is default page template?
Solution: Here I'll give you some options to address.
First:
<?php
if ( basename(get_page_template()) === 'page.php' ) {
// some code
}Second:
<?php
if ( is_page() && !is_page_template() ) {
// some code
}Sources: