I'm using the array-grid extjs example to try and fit a gridpanel into a container window. The problem is on resizing the container window, the gridpanel doesn't automatically fit the new size. As I understand it that's how it's supposed to work. Here's the link to the example: http://www.extjs.com/deploy/dev/examples/grid/array-grid.html What I've done is changed the following.. // Added to gridpanel config layout: 'fit', viewConfig: { forceFit: true } // Window container var gridWindow = new Ext.Window({ items: [ grid ] }); // Instead of grid.render, use gridWindow.show(); gridWindow.show();