Accessibility Support
Out of the box, the Telerik and Kendo UI Captcha provides extensive accessibility support and enables users with disabilities to acquire complete control over its features.
The Captcha is compliant with the Web Content Accessibility Guidelines (WCAG) 2.2 standards and Section 508 requirements, follows the Web Accessibility Initiative - Accessible Rich Internet Applications (WAI-ARIA) best practices for implementing the keyboard navigation for its component role, provides options for managing its focus and is tested against the most popular screen readers.
WAI-ARIA
This section lists the selectors, attributes, and behavior patterns supported by the component and its composite elements, if any.
No role attribute is implemented as the html input type="text" element is sufficient for definining purpose of the component.
| Selector | Attribute | Usage |
|---|---|---|
.k-captcha-image>img | alt | The Captcha image must have an alt tag, so that the. |
.k-captcha-image-controls>.k-button | role=button or nodeName=button | The image control buttons must have an appropriate role. |
aria-label or title | Each button must have an accessible name as they are all represented by icons and no text is available in their contents. | |
.k-captcha-input .k-input-inner | role=textbox or nodeName=input | Describes the role of the component. |
label for or aria-label or aria-labelledby | The input needs an accessible name to be assigned to it. | |
aria-invalid=true | Attribute is rendered only when the captcha is in form and announces the valid state of the component. | |
.k-disabled .k-input-inner | disabled=disabled or aria-disabled=true | Attribute is rendered only when the textbox is disabled. |
.k-captcha-input>input | type=hidden | The hidden input holding the Captcha ID value so that the remote could validate the user input. |
Managing the Focus
Tab Sequence follows the dom elements order. The focus order is as follows:
- Captcha image
- Reset button
- Audio button
- Input
When audio button is clicked (enter or space) the volume control (Slider component) is focused.
Keyboard Shortcuts
| Shortcut | Behavior |
|---|---|
Tab | Navigates to the next Captcha element. |
Shift+Tab | Navigates to the previous Captcha Element. |
Enter | Presses the focused Captcha button. |
Space | Presses the focused Captcha button. |
Arrow Up | Increases the Audio control volume. |
Arrow Down | Decreases the Audio control volume. |
Testing
The Captcha has been extensively tested automatically with axe-core and manually with the most popular screen readers.
Screen Readers
The Captcha has been tested with the following screen readers and browsers combinations:
| Environment | Tool |
|---|---|
| Firefox | NVDA |
| Chrome | JAWS |
| Microsoft Edge | JAWS |
