Components: Tab & Accordion

Guides tab and accordion implementation for organizing content without excessive vertical space. Two layout patterns: vertical accordion (FAQ-style, stacked) and horizontal tabs (how-to style, side-by-side). Both improve UX by reducing scroll; SEO impact depends on implementation and content placement.

When invoking: On first use, if helpful, open with 1–2 sentences on what this skill covers and why it matters, then provide the main output. On subsequent use or when the user asks to skip, go directly to the main output.

Layout Patterns

Mobile: Vertical accordion works well on small screens (natural scroll). Horizontal tabs can feel cramped—consider accordion, dropdown, or full-width tab bar that scrolls.

SEO: Is It Friendly?

Google's position: Google indexes and ranks content inside tabs and accordions fully; hidden content receives full weight (confirmed since 2016 mobile-first indexing). Gary Illyes: "we index the content, its weight is fully considered for ranking."

Practical nuance: Some tests show always-visible content outperforms hidden content in rankings. Reserve tabs/accordions for secondary content; place primary, keyword-critical content in visible areas.

Indexing Requirements

Content must be in the DOM on page load. Google does not simulate user clicks; it cannot "click" tabs to discover content.

Recommendation: Server-render all tab content in the initial HTML; use CSS/JS only to show/hide. Prefer <details>/<summary> or equivalent server-rendered markup. See rendering-strategies for SSR, SSG, CSR and crawler visibility.

Horizontal Tabs: More Tabs, More Content?

Technically: Yes—if all content is in the DOM at load, more tabs = more indexable content. Mobile-first indexing gives full weight to tabbed content in HTML.

Strategically: Not always. Signal dilution occurs when many tabs = many different topics on one page. Google may struggle to understand which query the page should rank for; topical authority and keyword focus get spread thin.

When many horizontal tabs work: All tabs semantically related to one query (e.g., one how-to, one product). When to use separate pages: Each tab is a distinct topic deserving its own URL, crawl, and ranking opportunity.

Implementation

Native HTML (Recommended)

Use <details> and <summary>—no JavaScript required; accessible; crawlable.

<details open>
  <summary>First question (expanded by default)</summary>
  <p>Answer content here.</p>
</details>
<details>
  <summary>Second question</summary>
  <p>Answer content here.</p>
</details>

• First tab/accordion: Add open attribute so it's expanded by default
• <summary>: Must be first child of <details>; acts as toggle
• Progressive enhancement: Style with CSS; add JS only if needed (e.g., close others when one opens)

JavaScript-Dependent Tabs

If using JS-only tabs: ensure all tab content is in the DOM at page load, not loaded via AJAX on click. Google does not simulate tab clicks. Prefer <details>/<summary> or server-rendered HTML. See rendering-strategies.

Avoid

• Content loaded only after user click (AJAX, lazy-loaded via fetch)—crawlers will not index it
• display: none or visibility: hidden for primary content—Google may treat differently
• Many tabs with unrelated topics on one page—causes signal dilution; use separate URLs instead

Content Best Practices

Use Cases

Schema & Rich Results

• FAQ (vertical accordion): FAQPage JSON-LD; schema must match on-page content exactly; see schema-markup, faq-page-generator
• How-to (horizontal tabs): HowTo schema for step-by-step content; see howto-section-generator, schema-markup, featured-snippet
• Other tabs: No specific schema; ensure semantic HTML (headings, structure)

UX & Accessibility

• Visual indicator: Arrow, plus/minus, or chevron to show expand/collapse state
• Keyboard: <details>/<summary> natively keyboard-accessible
• Core Web Vitals: Avoid layout shift (CLS) when expanding; reserve space or animate smoothly
• Mobile: Touch targets ≥44×44px; vertical accordion often better than horizontal tabs on small screens (tabs can be cramped; accordion scrolls naturally)

Pre-Implementation Checklist

• All tab/accordion content in DOM at page load (no AJAX on click)
• Primary ranking content visible, not hidden
• First tab/accordion expanded by default
• Using <details>/<summary> or equivalent server-rendered HTML
• Headers descriptive; keywords natural
• Tabs share one topic (avoid signal dilution); if different topics, consider separate pages
• For FAQ: FAQPage schema matches content

Related Skills

• faq-page-generator: FAQ structure, answer length, schema; accordion is common FAQ UI
• howto-section-generator: HowTo section; steps in tabs vs FAQ; JSON-LD alignment
• featured-snippet: Answer-first, H2/H3; content in accordions can be extracted
• schema-markup: FAQPage for FAQ accordions; HowTo for step-by-step tabs
• content-strategy: Pillar/cluster architecture; when to use separate pages vs tabs
• toc-generator: Collapsible TOC; similar disclosure pattern
• content-optimization: Word count, structure, multimedia in expandable sections
• rendering-strategies: SSR, SSG, CSR; content in initial HTML for crawlers