Last updated: January 30, 2019
Update: Please see our Java support in Google Chrome article for the latest information on how to view Java content in Chrome. The workaround described below is no longer supported by Chrome. macOS users please see Java support in Safari 12.
Looking to enable Java in Google Chrome 42 and higher? Did you start seeing This plug-in is not supported after upgrading Chrome? You, and everyone else who uses Chrome to view Java content in their web browser.
When Google released Chrome 42, it disabled some historically problematic browser plug-ins by default. Plug-ins, such as Java from Oracle and Silverlight from Microsoft, use an API from the 1990s called Netscape Plugin API (NPAPI). The issue you have encountered is that Google Chrome 42 (as well as later versions) disabled NPAPI by default, and with it, the Java plug-in (among other plug-ins). With the updated browser, when you visit web pages with Java content, you see a gray area with a puzzle piece display in its place instead. Mouse-over the gray area, and the message This plug-in is not supported accompanies it.
Fortunately, a quick and easy work-around exists to restore NPAPI to Google Chrome by default. To make your Java content available, follow these steps.
1. Upgrade to Google Chrome 42 (or the latest version up to Chrome 44). NPAPI is enabled by default in Chrome 41 and earlier. Please note that this option is no longer present in Google Chrome 45 or later. See How to use Java in Google Chrome 45+.
2. In a Google Chrome window, type or copy/paste this line into the address bar: chrome://flags/#enable-npapi
Click the Enable link under Enable NPAPI Mac, Windows.
3. For your change to take effect, click the Relaunch Now button at the base of the page.
Once Google Chrome relaunches, the Java content will display once again in the browser window. The plug-ins will still be subject to the previous blocking restrictions you may have encountered with Chrome in the past. You may need to give the plug-ins permission to run even with NPAPI enabled.
To disable NPAPI again if needed, return to the chrome://flags/#enable-npapi page, and click the Disable link under Enable NPAPI Mac, Windows.
Monobrowser Chrome acolytes also have the option of installing Chrome extensions like IE Tab. IE Tab emulates functionality within Chrome, such as Java and Silverlight (and other technologies that use NPAPI) that is found in other web browsers. The extension also allows you to set up Auto URLs that automatically open specified URLs using IE Tab. By doing so, you may automatically load frequently visited pages that included Java content to open in IE Tab.
But look smart. This work-around will only be an option for you to use until September 2015. At that point, the ability to enable and disable NPAPI is scheduled to be removed from Google Chrome for good.