i solved that by setting size inside vaadin
window.setHeight(“550px”);
window.setWidth(“800px”);
VerticalLayout mainLayout = new VerticalLayout();
setContent(mainLayout);
mainLayout.setHeight(“550px”);
mainLayout.setWidth(“800px”);
Dont know why i need to set both window as well as layout height and width … why cant setting size of window and just setting layout to sizefull should not work ?