How to open Javadoc JAR file in web browser Rename the file gander-no-op-3.1.0-javadoc.jar to gander-no-op-3.1.0-javadoc.zip Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder gander-no-op-3.1.0-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 "gander-no-op-3.1.0-sources.jar" -d "gander-no-op-3.1.0-javadoc" -subpackages