Simple 404 Logger
I couldn’t find a plugin suitable for logging 404 errors in WordPress which didn’t either have security problems, peformance problems or way too many features that I don’t need.
The Simple 404 Logger plugin is the simplest easiest to use solution I could come up with. It simply logs each 404 request once and overwrites that request every time a new one is made.
Future improvements will likely include the ability to selectively remove URLs or even all URLs from the logs. Once a problem has been fixed, it would make sense to remove it from the log.