Cell formatters are a set of predefined formatters that can be applied to cells. They will format the cell text on the client-side and present it in a specific way. The list of currently available cell formatters includes Integer, Number, Currency, CheckBox, Link and Mail.

Each formatter comes with its own set of properties, e.g. thousands separator, decimal places, target for links, etc. Please, take a look at the ASPX tab for samples.
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="default.aspx.cs" Inherits="JQSuiteASPNETExample.examples.functionality.formatters._default" %>
<%@ Register Assembly="Trirand.Web" TagPrefix="trirand" Namespace="Trirand.Web.UI.WebControls" %>

<!DOCTYPE html>
<html lang="en-us">
<head id="Head1" runat="server">
    <meta charset="utf-8">
    <title>jqGrid for ASP.NET WebForms - cell formatters - built-in</title>
    <!-- The jQuery UI theme that will be used by the grid -->
    <link rel="stylesheet" type="text/css" media="screen" href="http://code.jquery.com/ui/1.12.1/themes/redmond/jquery-ui.css" />
    <!-- The jQuery UI theme extension jqGrid needs -->
    <link rel="stylesheet" type="text/css" media="screen" href="/themes/ui.jqgrid.css" />
    <!-- jQuery runtime minified -->
    <script src="/js/jquery-3.2.1.min.js" type="text/javascript"></script>
    <!-- The localization file we need, English in this case -->
    <script src="/js/trirand/i18n/grid.locale-en.js" type="text/javascript"></script>
    <!-- The jqGrid client-side javascript -->
    <script src="/js/trirand/jquery.jqGrid.min.js" type="text/javascript"></script>    
    <style type="text/css">
        body, html { font-size: 80%; }    
    <form id="form1" runat="server">
       <trirand:JQGrid ID="JQGrid1" runat="server" Width="675px">
                <trirand:JQGridColumn DataField="Integer" Width="50">
                        <trirand:IntegerFormatter DefaultValue="No Value Set" ThousandsSeparator="," />
                <trirand:JQGridColumn DataField="Number" Width="75">  
                        <trirand:NumberFormatter DecimalPlaces="1" DecimalSeparator="." ThousandsSeparator=" " />
                <trirand:JQGridColumn DataField="Currency" Width="85" Editable="true">
                        <trirand:CurrencyFormatter DecimalPlaces="1" DecimalSeparator="." 
                                   Prefix="$" Suffix=" USD" ThousandsSeparator=","  />
                <trirand:JQGridColumn DataField="Email" Width="80">
                        <trirand:EmailFormatter />
                <trirand:JQGridColumn DataField="Link" Width="80">
                        <trirand:LinkFormatter Target="_new" />
                <trirand:JQGridColumn DataField="CheckBox" TextAlign="Center" Width="50">
                        <trirand:CheckBoxFormatter />
            <ToolBarSettings ShowEditButton="true" />
            <AppearanceSettings ScrollBarOffset="0" />
       <br /><br />
       <trirand:codetabs runat="server" id="DataTableCodeTabs"></trirand:codetabs>    
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using Trirand.Web.UI.WebControls;

namespace JQSuiteASPNETExample.examples.functionality.formatters
    public partial class _default : System.Web.UI.Page
        protected void Page_Load(object sender, EventArgs e)
            if (JQGrid1.AjaxCallBackMode == AjaxCallBackMode.RequestData)
                JQGrid1.DataSource = GetData();

        private DataTable GetData()
            DataTable dt = new DataTable();
            dt.Columns.Add(new DataColumn("Integer", typeof(int)));
            dt.Columns.Add(new DataColumn("Number", typeof(decimal)));
            dt.Columns.Add(new DataColumn("Currency", typeof(decimal)));
            dt.Columns.Add(new DataColumn("Email", typeof(string)));
            dt.Columns.Add(new DataColumn("Link", typeof(string)));
            dt.Columns.Add(new DataColumn("CheckBox", typeof(bool)));

            dt.Rows.Add(new object[] { "200000", "60000000.34", "34.21", "john.smith@yahoo.com", "http://www.yahoo.com", true });
            dt.Rows.Add(new object[] { "1600000", "7522233100.21", "244.51", "joe.woe@google.com", "http://www.google.com", true });
            dt.Rows.Add(new object[] { "430150", "6644000160", "1700", "julia.bergman@bing.com", "http://www.bing.com", false });
            dt.Rows.Add(new object[] { "125330", "20003340.99", "4678321", "roy.corner@msn.com", "http://www.msn.com", true });

            return dt;

Switch theme:

Theming is based on the very popular jQuery ThemeRoller standard. This is the same theming mechanism used by jQuery UI and is now a de-facto standard for jQuery based components. The benefits of using ThemeRoller are huge. We can offer a big set of ready to use themes created by professional designers, including Windows-like themes (Redmond), Apple-like theme (Cupertino), etc. In addition to that any jQuery UI controls on the same page will pick the same theme.

Last, but not least, you can always roll your own ThemeRoller theme, using the superb Theme Editor

To use a theme, simply reference 2 Css files in your Html <head> section - the ThemeRoller theme you wish to use, and the jqGrid own ThemeRoller Css file. For example (Redmond theme):

<link rel="stylesheet" type="text/css" media="screen" href="/themes/redmond/jquery-ui-1.8.2.custom.css" />
<link rel="stylesheet" type="text/css" media="screen" href="/themes/ui.jqgrid.css" />