The end user is not told or asked, which, in my opinion, is the way it should be.
I used Shift-Escape to bring up the Google Chrome Task Manager and saw that the Flash plugin was using a lot of ram and CPU cycles.It is packaged one way for use with Internet Explorer (an Active X control) and another way (referred to as the plugin version) for use with Firefox and Opera.Then along came Chrome with its own embedded copy, an idea that Microsoft copied with the desktop edition of Internet Explorer 10 and 11 on Windows 8.If your browser tries to download a file, Flash is not installed. But current browsers download the file rather than displaying it as a web page.Update March 28, 2017: I had not used this Flash tester in a long time. I am told that Chrome version 44 and earlier, that support NPAPI plugins, would display this.The most useful thing I have written about Flash was: A handy tip about updating Flash in the Chrome browser April 14, 2016.It walks you through using CHROME://COMPONENTS to update just the Flash Player in Chrome without updating the rest of the browser.Many times the Chrome browser has reported that it was up to date, yet Flash was not.This site (page really) started as way for me to easily find the main Adobe Flash tester page (links at the top above) which reports both on the installed copy of Flash in your browser and the latest version for assorted operating systems.In early Feb 2014 it was only displaying the first 3 sections of the Flash version number, which has 4 sections. As of May 2015, the bug was back, it reported only that v17.0.0 was installed.The bug still existed July 15, 2015 (Chrome on Windows 7 reported that version 18.0.0 was installed).