If you are a publisher using Google Ad Manager to serve ads on your site, you will want to be using Google Publisher Console too. It's a useful free tool that enables you to troubleshoot problems with your ad slots and ad delivery generally.
The Console opens in a panel at the bottom of the page you are inspecting, rather like Chrome DevTools, with an optional overlay on the ads themselves. This allows you to both see and troubleshoot your ad slots simultaneously. It looks like this (click on the image to see a bigger version):
However, despite using Google Publisher Console regularly, I always struggle to remember how to launch the thing. And I think that is because I never do it the same way twice! Here are three different ways that I seem to rotate between:
The Console will open in a new tab. Meanwhile, in your original tab, Google Ad Manager will also list information about your ad slots and the line items that are being served to them.
There are several different parameters that can be appended to a URL to launch Google Publisher Console. The one that I learned about first is ?google_force_console=1. So for example, if I wanted to troubleshoot the ad serving on this very website's homepage, I would go to:
Reading around the subject, I have also learned that the slightly shorter ?google_console=1 works just as well. So again, for this site's homepage it would be:
Finally, when using Google Ad Manager's delivery tools to launch the Console, you will notice that ?dfpdeb is appended to the URL instead. (I am safe in assuming that 'dfp' stands for Doubleclick for Publishers, the old name for Google Ad Manager - but I am not sure what 'deb' stands for. Delivery box?) Anyway, my example here would be:
All three options do exactly the same thing. Of course, like the other methods of launching the Console, they will only work on websites that use the Google Publisher Tag (that is, contain Google Ad Manager ad units).
Note that Google warns "this option doesn't work on all websites" - but doesn't explain the situations under which it will or won't work.
Google Publisher Console can also be enabled using Google Tag Assistant, a free extension for the Chrome browser.
So there you go - three ways to launch Google Publisher Console. I should mention that Google Ad Manager Help also has a page listing three ways to do this, and two of the ways are different to mine (making at least five ways in total).