How to open Javadoc JAR file in web browser Rename the file json-data-generator-1.16-javadoc.jar to json-data-generator-1.16-javadoc.zip Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder json-data-generator-1.16-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 "json-data-generator-1.16-sources.jar" -d "json-data-generator-1.16-javadoc" -subpackages