--- path: components/combobox/overview title: Overview position: 1 seo_title: Overview of the ComboBox Component seo_description: Learn about the basic features of the Telerik and Kendo UI ComboBox component and its types, check out the extensive set of available options in its live demo, and master its appearance by setting the size, fill mode, and border radius as you wish on the fly. --- ## ComboBox Overview A ComboBox is a user interface (UI) element combining a drop-down list or list box and an editable text field. The control displays a set of available options and allows the user to select from them in two ways: by typing into the text field and bringing up an option from the set or by directly selecting the desired options from the set. ### Live Demo ### Appearance The ComboBox provides built-in styling options that grant visually appealing and flexible rendering experience. Apart from the default vision of the Telerik and Kendo UI ComboBox, the component supports alternative styling options which enable you to configure the individual aspects of its appearance. #### States Depending on the action you want to imply through its appearance, the Telerik and Kendo UI ComboBox can acquire the following states which you can set by using the following classes: * The normal state indicates that the ComboBox is ready to use but the user is not interacting with it yet. The control displays the currently selected item, which appears as text within the input field. * `k-hover`—Тhe hover state of a ComboBox is applied when the user hovers over the component. This state indicates that the control is interactive and enabled. Note that the ComboBox has an icon button that opens the drop-down list. The hover state of the icon button is independent of the hover state of the ComboBox and indicates that the user can interact with the icon button. * `k-focus`—The focus state is triggered when a user selects the ComboBox with the mouse or keyboard. By displaying a highlighted border, this state indicates that the control is active and ready to receive user input. * `k-invalid`—The invalid state is applied when the user enters or selects an unexpected value. By displaying a validation error icon and a red border, this state indicates an error in the input. * `k-invalid k-focus`—The invalid focus state of the ComboBox is a result of spotlighting a ComboBox whose value or input type does not pass the validation requirements. * `k-disabled`—The disabled state indicates that a ComboBox is temporarily unusable because, for example, the page requires additional user input, or something important is missing before users continue to the next step. To indicate that they are unavailable, ComboBoxes appear grayed-out. #### Anatomy The anatomy of the ComboBox summarizes the visual and functional elements of the component. The main elements include a text input field, an icon button, and a drop-down list that shows all available options. The text input displays the currently selected item or a temporary placeholder text. It allows the users to type their own value or edit the currently selected item. The ComboBox also includes a label, hint text, and clear button that lets the user clear the current selection and revert to the placeholder text. > When using the control as a part of a Form component, the label and hint text are optional. The next image shows the anatomy of a ComboBox and includes the following elements: ![A Telerik and Kendo UI ComboBox component with the input field, icon button, label, hint text, placeholder or preselected value, Clear icon, selected item, and drop-down list elements.](images/components-combobox-overview-anatomy.png "Anatomy and elements of a Telerik and Kendo UI ComboBox including the input field, icon button, label, hint text, placeholder or preselected value, Clear icon, selected item, and drop-down list elements.") #### Size The ComboBox provides the `size` configuration option that enables you to control how big or small the rendered ComboBox will be. ComboBoxes also provide options for size customization. `size` provides the following available options: * `small`—Renders a small ComboBox, which is suitable for compact components, such as Toolbars, where the available space is limited. * `medium` (default)—Renders a medium ComboBox. * `large`—Renders a large ComboBox that is suitable for adaptive designs. * `none`—Does not set a `size` and allows you to add your own, custom value. ![Three Telerik and Kendo UI ComboBox components demonstrating the small, default medium, and large sizes respectively.](images/components-combobox-overview-size.png "Available sizes in the Telerik and Kendo UI ComboBox component including small, default medium, and large.") #### Fill Mode The ComboBox provides the `fillMode` configuration option that enables you to control the way in which color is applied to the rendered ComboBox. ComboBoxes also provide options for fill-mode customization. `fillMode` provides the following available options: * `solid` (default)—The solid ComboBox puts a stronger emphasis on the action it indicates and draws the user attention. This is the widely used common style. * `outline`—The outline ComboBox provides a minimalist look and can be a good choice when you want the ComboBox to blend in with the background or other UI elements. * `flat`—The flat ComboBox has a plain and discreet look, making it a good choice when you need an unobtrusive ComboBox that doesn't distract the users from the elements with higher importance. ![Three Telerik and Kendo UI ComboBox components demonstrating the default solid, outline, and flat fill modes respectively.](images/components-combobox-overview-fill-mode.png "Available fill modes in the Telerik and Kendo UI ComboBox component including default solid, outline, and flat.") #### Border Radius The ComboBox provides the `rounded` option that enables you to control the border radius of the rendered ComboBox. By default, the ComboBoxes are rendered with a medium border radius. If required, you can customize the border-radius of the ComboBox. `rounded` provides the following available options: * `small`—Renders a border radius of 2 px. * `medium` (default)—Renders a border radius of 4 px. * `large`—Renders a border radius of 6 px. * `full`—Renders a border radius of 9999 px. * `none`—Does not set a `rounded` value and allows you to customize the configuration. ![Four Telerik and Kendo UI ComboBox components demonstrating the small, default medium, large, and full fill modes respectively.](images/components-combobox-overview-border-radius.png "Available border radiuses in the Telerik and Kendo UI ComboBox component including small, default medium, large, and full.") ### Framework-Specific Documentation For the framework-specific information about the UI components, refer to the respective product documentation: ![Kendo UI for Angular logo.](/images/angular-logo.svg) ![Telerik UI for Blazor logo.](/images/blazor-logo.svg) ![Kendo UI for jQuery logo.](/images/jquery-logo.svg) ![KendoReact logo.](/images/react-logo.svg) ![Kendo UI for Vue logo.](/images/vue-logo.svg) ![Telerik UI for ASP.NET Core logo.](/images/core-logo.svg) ![Telerik UI for ASP.NET MVC logo.](/images/mvc-logo.svg)