This is a quick tutorial on how to find the ID of a page or post in WordPress. There are 3 easy ways to do that:
Hover Over Page Title

First go to Pages / All Pages. Then hover over the page title you want to know the ID for. On the bottom of your browser, you will then see the URL that would be opened if you click the page. Where it says post=11, that indicates the ID of the page. In this case the page ID is therefore 11.
URL when Editing a Page

The second way is to simply click into any page or post. In the browser you will then see the URL on the top. There again, like in option 1, you will see a parameter post=2 whereby the number indicates the page ID. Therefore, in this case, the page ID is 2.
Find Page ID in Page Source

The third option is a bit more tricky but nice, as you don’t have to be logged into the backend, so you can do it on any WordPress website, even one you don’t own.
To get started, make a right click with your mouse anywhere on the page and pick View Page Source.

A new tab with the code should open. There click Ctrl – S on your keyboard to open search. Type in <body and you’ll see a line that starts with that. In the class attribute you will then see a class that is called page ID, the number at the end of that class is, as you can guess, the actual page ID of that page. Here in this example, the page ID is therefore 3.
That’s it. Easy enough.