What is a semantic index in web scraping?

What is a semantic index?

When you request a page that has already been scraped, the index returns the stored result immediately rather than re-crawling the live site. This dramatically reduces latency for repeat requests.

Metric

Live Scrape

Cached

Latency

2–10 seconds

50–200ms

Cost

Full crawl cost

Reduced

Availability

Depends on target site

Always available

Why it matters

• AI agents: Real-time decision-making requires instant access to data
• User-facing apps: Sub-second response times are expected
• High volume: Cache hits reduce both cost and processing time

Olostep's maxAge parameter lets you define the maximum acceptable age for cached data—instant results whenever fresh data already exists.

Key Takeaways

Semantic indexing delivers cached web data in milliseconds, making it essential for real-time AI applications and user-facing products that can't afford multi-second scraping delays.