Definition
App Indexing makes app content discoverable via web search (Google Search, Safari). Universal Links + NSUserActivity enable Spotlight and Safari results (Apple); Firebase App Indexing (Google) exposes app content to Google Search. Impact: Drive app installs from web search; content-heavy apps benefit most.
How It Works
Apple
- NSUserActivity indexed by Spotlight (on-device)
- Safari can surface Universal Links in search (limited, contextual)
- Content must be marked in app code
- Firebase App Indexing sends app content to Google Search
- URLs indexed; users can install app from search results
- Impact: Declining post-2023; focus shifted to web-to-app pathways
Formulas & Metrics
Web Search to App Install Rate:
- Benchmark: 5–15% of web search traffic installs app
- Content-heavy apps (recipes, tutorials, articles): higher rates (15–30%)
Best Practices
- Apple: Implement NSUserActivity for indexable content
- Google: Migrate from Firebase App Indexing to web-to-app Googlebot crawling
- URL Structure: Consistent scheme across web + app
Examples
- Recipe App: Article indexed in Google Search → install button shown → 10% install rate from search
- Tutorial App: Blog posts indexed → web search drives discovery
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Last updated: 2026-04-08