The OpenLayers `TransitionEffect='resize'` property is not working while using GeoWebcache service of GeoServer var demolayer = new OpenLayers.Layer.WMS( "Eg", "http://localhost:8080/geoserver/gwc/service/wms", { layers: 'Eg', format: 'image/gif' , tiled: true, tilesorigin: [29.06213671874999, 28.912181118327] }, {attribution: '©copy rights', tileSize: new OpenLayers.Size(256,256)}, { transitionEffect: 'resize' } );