Recently I was performing an audit on my Multisite network to see, among other things, which plugins just weren’t in use any more.
The trouble is that when you have multisite setup, you have to install a plugin at the network level and then activate the plugins on the individual sites that you want to activate it on (unless you network activate the plugin). Thus, when you’re frequently activating and deactivating plugins on multiple sites, you don’t want to necessarily delete the plugin in case it’s active on other sites as well.
As my intuition would prove me right, I figured there had to be a plugin which would show you which plugins were active on which sites on your network, so that you could remove the ones that weren’t in use. That was when I discovered Network Plugin Auditor.
Network Plugin Auditor does a few things. First of all, it performs the exact task I wanted it to. It allows me to look at my list of network installed plugins and it tells me which sites each plugin is active on. See below for an example:
That makes it very easy to identify the orphan plugins and remove them accordingly.
Secondly, it adds a column to your Network Site list, to show you all of the plugins active on each site, like in the image below:
And lastly, as an added bonus, it does the same for your network-activated themes. You can view your network theme list and see which themes are active on which sites, highlighting which themes are not in use. One issue I saw with this is that, if there are any child themes in use, the plugin will not highlight the parent theme that it depends on, so you could inadvertently delete a parent theme and break one or more sites.
Nonetheless, it’s an extremely useful tool for auditing your network and tidying up after a plugin installation spree.