9.3SEO Benefits of Accessibility

Search engines and screen readers consume web content in similar ways. Accessible websites naturally rank better.

Accessibility Practice	SEO Benefit
Descriptive alt text on images	Image search ranking, richer snippets
Heading hierarchy (h1-h6)	Content structure signals to crawlers
Semantic HTML (<nav>, <main>, <article>)	Better content understanding
Descriptive link text	Higher quality link signals
Page language declaration	Correct language indexing
Fast-loading pages (no heavy overlays)	Core Web Vitals / page experience ranking
Mobile accessibility	Mobile-first indexing compatibility

Measuring the SEO Impact

# Compare Lighthouse scores: accessible vs non-accessible versions
def measure_seo_impact():
    """
    Track SEO metrics before and after accessibility improvements.
    """
    metrics = {
        "before_a11y": {
            "lighthouse_seo_score": 72,
            "lighthouse_a11y_score": 45,
            "core_web_vitals_pass": False,
            "organic_traffic_monthly": 50000,
        },
        "after_a11y": {
            "lighthouse_seo_score": 94,
            "lighthouse_a11y_score": 97,
            "core_web_vitals_pass": True,
            "organic_traffic_monthly": 68000,  # 36% increase
        },
    }
    return metrics