How to open Javadoc JAR file in web browser Rename the file yui-parent-1.4.21-javadoc.jar to yui-parent-1.4.21-javadoc.zip Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder yui-parent-1.4.21-javadoc Double click index.html will open the index page on your default web browser. How to generate Javadoc from a source JAR? Running the command javadoc: javadoc --ignore-source-errors -encoding UTF-8 -sourcepath "yui-parent-1.4.21-sources.jar" -d "yui-parent-1.4.21-javadoc" -subpackages