What is NPAPI plugins in Google Chrome?

NPAPI stands for Netscape Plugin Application Programming Interface. It is a plugin used by a majority of browsers. A plugin is what handles certain content types. Before NPAPI was adopted, whenever one came across unknown content types ( For instance, a PDF file or a video), the user had to download the file and then execute it. Now, whenever a browser comes across a unknown file type it loads the associated plugin and streams the concerned data to it. The plugin then renders the content.

Now, in view of the security concerns, Google has decided to drop support for the NPAPI plugin. In Chrome version 42, the NPAPI will be disabled and can be enabled. However, from Version 45 it will be completely phased out.

The full form of NPAPI is Netscape Plugin Application Programming Interface. As the name suggests, it was developed by Netscape. With the help of this plugin, a web browser can directly execute a file (e.g., mp3) without downloading it.

Not only Google Chrome, Mozilla Firefox and Internet Explorer also uses this plugin. Google has decided not to use this plugin in Chrome 45 and latter verions.