Tomcat default port is 8080 but many times other Java application also uses 8080 like any other web-server Resin or Jetty and starting tomcat may result in java.net.BindException:Address already in use: JVM_Bind 8080. In order to avoid this exception you can change default port of tomcat from 8080 to some other port e.g. 8081 or 8082. Though don't change to tomcat port which is likely to be used by tomcat itself e.g. 8443 is used by tomcat https port. Use port which is most likely to be free. In this tomcat tutorial we will see how to change default port 8080 for http protocol in tomcat and port 8443 port for https protocol in tomcat.