Tab Component with :checked Hack vs JS
Implement a tab interface using the CSS :checked technique and compare it to a JavaScript approach.
Tab Component with :checked Hack vs JS is a free CSS Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the CSS Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Tab Component Requirements
A tab component needs: visual indicator of the active tab, associated panel shown/hidden on selection, keyboard navigation between tabs, and accessible ARIA attributes. These can be achieved with pure CSS using the :checked hack or with JavaScript for better accessibility.
The :checked Hack
Hidden radio inputs act as state: each tab is a <label> linked to a radio input. When a radio is checked, CSS sibling combinators show the corresponding panel and style the active tab label. Zero JavaScript required.
input[type="radio"]:checked + label { border-bottom: 2px solid var(--color-primary); }
input#tab-1:checked ~ #panel-1 { display: block; }:checked CSS Architecture
Place radio inputs, then all labels (tabs), then all panels in the same container. Use the general sibling combinator (~) to connect a checked radio to its corresponding panel. Panels default to display: none; the matching one gets display: block.
Limitations of :checked Approach
The :checked hack cannot update ARIA attributes (aria-selected, aria-controls), cannot enable Arrow key navigation between tabs, and DOM ordering constraints (inputs before panels) may conflict with visual design requirements. These gaps limit true accessibility.
JavaScript Tab Component
A JS tab component listens for click events on tab buttons, sets aria-selected on the active tab, updates aria-hidden on panels, and manages focus. This approach enables full ARIA compliance and keyboard interaction patterns per ARIA Authoring Practices.
ARIA Roles for Tabs
Use role="tablist" on the container, role="tab" on each tab button with aria-selected and aria-controls, and role="tabpanel" on each panel with aria-labelledby. Screen readers announce tab count, position, and selected state.
Keyboard Interaction Pattern
ARIA Authoring Practices for tabs: Tab key enters the tablist and focuses the active tab. Arrow Left/Right moves between tabs. Home/End jump to first/last tab. Each arrow key movement activates the focused tab (automatic activation pattern).
CSS for Active State
Style the active tab with a bottom border or background change using [aria-selected="true"] selector — works with both JS and :checked approaches. This keeps CSS in sync with the ARIA state attribute, avoiding dual state management.
[role="tab"][aria-selected="true"] {
border-bottom: 2px solid var(--color-primary);
color: var(--color-primary);
}Animated Indicator
An animated tab indicator slides between tabs: position an absolutely-positioned indicator element, use JavaScript to set its left position and width to match the active tab's dimensions, and animate with transition: left 200ms ease, width 200ms ease.
Responsive Tab Overflow
When tabs overflow their container on small screens, use horizontal scrolling (overflow-x: auto; scrollbar-width: none) or collapse into a select dropdown on mobile. The select approach requires JS to sync the native select with the tab panel visibility.
CSS-Only vs JS: When to Use Each
Use the :checked hack for simple, non-critical UI where accessibility is not a priority constraint. Use JavaScript tabs for any production interface serving keyboard users, screen reader users, or applications requiring ARIA compliance in audits or legal requirements.
Knowledge Check
What is the primary accessibility limitation of the CSS :checked hack for tabs?
Summary
The :checked hack achieves CSS-only tab switching using radio inputs and sibling combinators but lacks ARIA and keyboard accessibility. JavaScript tabs with ARIA roles (tablist, tab, tabpanel), aria-selected management, and Arrow key handling provide the complete, accessible experience required for production components.
Frequently asked questions
Is the “Tab Component with :checked Hack vs JS” lesson free?
Yes — the full text of “Tab Component with :checked Hack vs JS” is free to read here on the web, and the CSS Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the CSS Academy course, upgrade to CoddyKit PRO.
What will I learn in “Tab Component with :checked Hack vs JS”?
Implement a tab interface using the CSS :checked technique and compare it to a JavaScript approach. You practise CSS Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start CSS Academy?
No prior experience is required. CSS Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Tab Component with :checked Hack vs JS” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this CSS Academy lesson?
Yes. Every CSS Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Card Component with CSS Custom Properties
- Modal and Dialog Styling
- Dropdown and Popover Patterns
- Tab Component with :checked Hack vs JS