How much does it cost to feed websites to Claude or GPT?

Feeding websites to Claude or GPT typically costs $0.001-$0.03 per page depending on page size and whether you preprocess the HTML. The math: a typical webpage is 20-50KB of HTML ≈ 5,000-15,000 tokens raw. At Claude Sonnet 4 input pricing of $3/M tokens, that's $0.015-$0.045 per page raw. Convert to clean markdown first (via AgentFetch, Jina Reader, or Firecrawl) and you cut that by 70-85%, landing at $0.001-$0.007 per page. Scraping infrastructure itself adds cost: Firecrawl charges roughly $0.001-$0.003 per page on paid tiers, Jina Reader is free with rate limits, AgentFetch has a free tier and paid plans for high volume. For a research agent that reads 50 pages per task, total cost is roughly $0.10-$0.30 per task with preprocessing vs $1-$2 raw. The dominant lever is preprocessing — using a fetch tool that returns markdown instead of HTML — followed by smart caching and avoiding redundant fetches. Browser-rendered JS pages cost more because they require Playwright/Chrome execution.