How to open Javadoc JAR file in web browser Rename the file image-comparison-4.4.0-javadoc.jar to image-comparison-4.4.0-javadoc.zip Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder image-comparison-4.4.0-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 "image-comparison-4.4.0-sources.jar" -d "image-comparison-4.4.0-javadoc" -subpackages