Another one that slows a lot of things down is if the application uses the console. Before you open the inspector, those methods are no-ops and just get skipped

Another one that slows a lot of things down is if the application uses the console. Before you open the inspector, those methods are no-ops and just get skipped, basically, but once open, all of those strings have to get copied and it can slow things down quite a bit. This isn't unique to the web, either, adding the verbose flag to most linux file utilities and then operating on a large set of files will be slower than without the verbose flag, too, just because printing to stdout takes time.