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Responsive, Adaptive and Elastic Capabilities

This article explains the responsive design capabilities RadTooltip offers. The Lightweight RenderMode of RadTooltip supports elastic design since Q3 2013.

Generally, responsive design means that the page and its content are able to adapt to different screen resolutions without deteriorating the user experience. This often includes changing the font size and having dimensions set in percent.

Elastic Design with RadTooltip

Figure 1: Comparison between appearance of a RadTooltip with regular font size and with increased font size


RadTooltip does not create elastic design by itself, but can fit in a pagethat follows this pattern. This means that RadTooltip does not support dimensions set in percent,but its Lightweight RenderMode supports changing the font size without breaking the control's appearance - if the new size is larger than the original,the elements in the control will simply increase their size as well to accommodate the text.This fluid layout is achieved by using em units for setting dimensions and paddings in the control, instead of px because em units are tied to the font size. This allows dimensions and sizes to scale with the font size.


As of 2016 Q1 SP1 RadTooltip takes the font-size of the page automatically. If the developer does not set it explicitly (Example 1), this is up to the client's browser and a common default value is 16px.

Example 1: Setting default font for the page with the default value for the Telerik controls.

body {
    font-size: 20px;
    font-family: "Segoe UI", Arial, Sans-serif;

Example 3: How to increase the font size of a RadTooltip. The effect can be seen in comparison in Figure 1.

<style type="text/css">
    /*div.RadToolTip*/ /*This rule can be used in versions prior to Q3 2015*/
        font-size: 18px;
<asp:Image ID="imgStatus" runat="server" Style="width: 100px; height: 100px; display: block; color: #000; margin: 100px auto; border: 1px solid red;" />
<telerik:RadToolTipManager ID="ttmInstallStatus" OffsetY="-1" HideEvent="ManualClose"
    ShowEvent="OnMouseOver" Width="400" Height="140" runat="server" RelativeTo="Element"
    Position="BottomCenter" EnableShadow="true" ShowCallout="true"
    Title="ToolTip Longer Title" EnableEmbeddedSkins="true" RenderMode="Lightweight">
        <telerik:ToolTipTargetControl TargetControlID="imgStatus" Value="Apple" />

See Also