Tab Navigation

Tabs organise related content under a shared context. The tab strip communicates the full set of available views; switching tabs swaps the content panel without a page navigation. They work best when all views share a heading, a primary action, or a common subject — tabs that have nothing to do with each other belong in separate pages.

When to Use Tabs — and When Not To

Tab Types

Choose the visual style that fits the layout context.

Underline / Indicator Tabs

A horizontal strip with a sliding underline or bottom border on the active tab. The lightest treatment — appropriate for page-level tabs where the tab strip sits inside the content area.

Overview  |  Activity  |  Settings
──────────

Contained / Boxed Tabs

Each tab is a distinct box; the active tab appears connected to the panel below. Higher visual weight — appropriate for prominent tab groups near the top of a screen or within a card.

Pill / Button Tabs

Rounded capsules that toggle between states. Lower emphasis — appropriate for secondary content switches within a section (not page-level). Often used for view toggles (e.g. "List / Grid / Map").

Anatomy

┌─────────────────────────────────────────────────┐
│  Tab A  │  Tab B  │  Tab C  │                   │  ← Tab strip (role="tablist")
├─────────┴─────────────────────────────────────────┤
│                                                   │
│   Tab panel content                               │  ← Tab panel (role="tabpanel")
│                                                   │
└───────────────────────────────────────────────────┘

• Tab strip: Fixed height (typically 40–48px). Does not scroll with the page — consider making it sticky when the page is long.
• Tab panel: Fills the remaining available height. The panel, not the tab strip, scrolls when content overflows.
• Active indicator: A 2–3px bottom border in --color-primary for underline tabs; filled background for contained/pill tabs.

States

Never disable the active tab. If content is unavailable, show it inside the panel with an explanation rather than disabling the tab.

Tab Overflow

When the tab strip is wider than its container, do not wrap tabs onto multiple lines; it destroys the strip metaphor. Three ways out, in order of preference.

Select fallback

Measure the strip; when its content is wider than its container, render a native <select> with the same options. Every option stays reachable at one glance and at any width, with nothing hidden off the edge, and the platform already gives touch users its picker.

Scrollable strip

The strip scrolls horizontally with a fade at the right edge to signal overflow. The platform convention on mobile, and fine when the user knows the set of tabs; it hides options from a first-time reader.

.tab-strip {
  display: flex;
  overflow-x: auto;
  scrollbar-width: none; /* hide scrollbar visually on desktop */
}
.tab-strip::after {
  content: '';
  position: absolute; right: 0;
  background: linear-gradient(to left, var(--color-surface), transparent);
  pointer-events: none;
}

"More" overflow menu

Show as many tabs as fit, then collapse the rest into a More ▾ dropdown. Update the "More" label when an overflowed tab is active: Settings ▾ (showing the active hidden tab name).

Whichever is used, mark the selected tab with an underline on that tab only; a rule under the whole strip competes with it. For desktop dashboards with many views, prefer a sidebar nav over overflow tabs.

Vertical Tabs

Use when there are 5+ tabs and the layout has a left sidebar. Vertical tabs allow longer labels without overflow issues and scale more gracefully.

• Fixed width sidebar (typically 200–240px) with tab labels stacked vertically
• Active tab: left border accent (3px solid --color-primary) + subtle background
• The main content area fills the remaining width

Keyboard Navigation

Tabs follow the ARIA "roving tabindex" pattern for within-strip navigation.

Auto-activate vs. manual activate: If switching tabs triggers a network request, use manual activation (arrow keys move focus, Enter activates) to avoid unnecessary fetches. If content is already loaded or cheap, auto-activation on arrow key is acceptable.

ARIA

<div role="tablist" aria-label="Product sections">
  <button
    role="tab"
    id="tab-overview"
    aria-selected="true"
    aria-controls="panel-overview"
    tabindex="0"
  >Overview</button>
  <button
    role="tab"
    id="tab-activity"
    aria-selected="false"
    aria-controls="panel-activity"
    tabindex="-1"
  >Activity</button>
</div>

<div
  role="tabpanel"
  id="panel-overview"
  aria-labelledby="tab-overview"
>…</div>

<div
  role="tabpanel"
  id="panel-activity"
  aria-labelledby="tab-activity"
  hidden
>…</div>

• aria-selected="true" on the active tab, false on all others
• tabindex="0" on the active tab, -1 on all others (roving tabindex)
• hidden attribute (or display: none) on inactive panels — screen readers skip hidden panels
• aria-label on the tablist when the heading above doesn't sufficiently describe the group

State Persistence

Remember the active tab across page loads and navigations:

• URL fragment or query param: ?tab=activity — the most robust approach; supports deep linking and browser back/forward
• localStorage: Acceptable for preferences (e.g. a preferred dashboard view) that don't need to be shareable
• Do not use sessionStorage — tabs closing lose the state unexpectedly

When the URL contains a tab param, jump to that tab on load even if it's not the first tab.

Nested Tabs

Avoid tabs within tabs. Nested tabbing creates confusion about scope — a user editing content in "Tab A › Sub-tab 2" has no clear mental model of what the outer tab means.

If you find yourself nesting tabs, reconsider the information architecture:

• Can the inner tabs become a secondary nav (pills, a sidebar within the panel)?
• Can the outer tabs become a top-level page nav instead?

One level of tabs maximum in the primary content area.

Review Checklist

• Are there 2–7 tabs, each sharing a common subject or context?
• Is the tab strip not wrapping to multiple lines on any target viewport?
• Is the active tab clearly distinguished by colour and/or indicator?
• Do hover and focus states meet contrast requirements?
• Are disabled tabs avoided (showing unavailability inside the panel instead)?
• Does keyboard navigation follow roving tabindex (←/→ between tabs, Tab into panel)?
• Is role="tablist", role="tab", role="tabpanel", and aria-selected set correctly?
• Are inactive panels hidden from the accessibility tree (hidden attribute)?
• Is the active tab persisted in the URL (for deep-linkable views) or localStorage?
• Are nested tabs avoided?
• Does tab overflow use a select, a scrollable strip or a "More" menu, never wrapping?
• Is the selected tab marked by an underline on that tab only, with no rule under the whole strip?