Full browser (AJAX) client is significantly slower than Internet Explorer (IE) Plugin

Accessing a QlikView application is observed as being significantly slower than accessing the same application with IE Plugin.

NOTE: In this comparison it is important to compare different sessions starting with a clear server side cache. 

The technical difference between the Internet Explorer (IE) Plugin and the full browser (AJAX) client leads to different load and update times for applications. 

The IE Plugin communicates directly with the QlikView Server (QVS) over the QVP protocol. This means that the data transfer is optimal, both in terms of data compression and transfer speed.

The AJAX client communicates over HTTP. XML based data is used as the data carrier in HTTP traffic, and this structurally has a large over head. The data also must pass through a webserver  when it is sent from the QlikView server to the browser. This means that more data is transferred and that it is processed an additional time, which leads to a slightly longer transfer time. 

As troubleshooting the comparison can be done on localhost, to exclude network related latency. If the issue appears to be related to the network, consider any possibilities that can affect the HTTP traffic, for example evaluate if firewalls or proxies affect the data. 

If IIS is used as webserver to host the QlikView application, try switching to QlikView webserver instead to evaluate if IIS is affecting the results. For further troubleshooting consult IIS documentation or local IIS administrator.