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Optimizing Performance

In this article we will go ahead and summarize the most important performance info we already have in our documentation resources. Optimization Tips series in the blogs:

By default each Telerik control serves a set of files (javascript code and stylesheets) needed for proper client-side operation and look.

When loading a page with several controls on it, the number of these files can become very large, often resulting in a reduced page load time and increased traffic. The reason for this problem is that browsers make separate requests to the server for each of these resources.

Usually this problem is overcome by disabling the automatic script and stylesheet serving the controls, combining them into a smaller set of files and manually registering the links to these files in the page.

This approach is not the best for a number of reasons:

  • you must extract the files from the assembly for each control release:

  • files become too large to be maintainable (or you have to write a script to merge the source files)

  • the number of the merged files you need to maintain can become very large depending on the control sets you have on different pages;

Nevertheless, by using RadScriptManager and RadStyleSheetManager controls, Telerik UI for ASP.NET AJAX suite gives developers the advantage of a simple drag-and-drop to achieve the combination of resources to a single request. All you need is to add a RadScriptManager to your page instead of the default ScriptManager and the javascript files will get combined into a single file. Putting an additional control – RadStyleSheetManager to the page makes the stylesheet requests combined into a single request. Both controls need an HttpHandler to be declared in the application's configuration file to operate properly. The handler can easily added using the Smart Tags of the controls.

The RadScriptManager and RadStyleSheetManager controls also let you download the resources the Telerik controls need from our CDN instead of using WebResource requests. To do that, set their CdnSettings-TelerikCdn property to Enabled. You can read more on the subject in the CDN Overview help article. Using the CDN takes load off your server and improves resource caching.

Downloading from the CDN, however, will result in a request for each individual file (script, stylesheet, font, etc.). You can improve the CDN performance even further by instructing the controls to fetch a combined resource of all scripts/base stylesheets for all the controls in a single request by toggling the Telerik.ScriptManager.TelerikCdn.CombinedResource and Telerik.StyleSheetManager.TelerikCdn.CombinedResource appSettings keys to enabled. This configuration is exposed for an individual instance via the CdnSettings-CombinedResource property.


RadGrid control provide a different solutions to optimize its performance. You can find more information in the help articles from the following list:


Below you can find a list of performance optimization help articles for RadEditor control:


You can read more information about optimization RadTreeView performance in Optimizing RadTreeView Performance help article.


Performance might degrade with lots of items and lots of combobox instances on the page. Optimizing the Combobox help article gives some hints how to achieve better performance.


Optimizing RadMenu Performance help article elaborates more on increasing the control performance.


You can find more information regarding performance optimization in Optimizing RadTabStrip Performance help article.

RadDatePicker, RadDateTimePicker and RadTimePicker

Performance problems can be caused by using the picker in list controls. You can check out the following articles which elaborate more on performance optimization.

RadDateInput, RadNumericInput, RadMaskedTextBox and RadTextBox

Performance problems can be caused by using these controls in templates of list controls. A better idea is to create an outside edit form similar to this example:

Client-side edit, update, delete and insert with RadControls for ASP.NET AJAX, WebServices and LINQ


RadTooltip and RadTooltipManager are quite lightweight but you can still optimize them if many controls are rendered on the page. You can find more infromation in Optimizing RadToolTip Performance help article.


You can check out the Optimizing RadScheduler Performance help article for some tips to optimize the control performance.


You can find a details information about optimizing RadHtmlChart control in Performance Optimizations help article.

RadAjaxPanel and RadAjaxManager

More detailed information is available in Optimizing Performance Using RadAjaxManager