How do I calculate bandwidth costs for web scraping?
Calculating bandwidth costs helps you budget for large-scale scraping projects and optimize resource usage.
Basic calculation:
- Measure the size of one page request (HTML + assets)
- Multiply by the number of pages you need to scrape
- Add overhead for failed requests and retries (typically 10-20%)
- Multiply by your proxy provider's cost per GB
Example calculation:
- Average page size: 2 MB (including images, CSS, JS)
- Target pages: 100,000
- Retry overhead: 15% (115,000 total requests)
- Total bandwidth: 2 MB × 115,000 = 230 GB
- Proxy cost: $5/GB
- Total cost: 230 GB × $5 = $1,150
Reducing costs:
- Block unnecessary resources (images, fonts, analytics scripts)
- Use headless browsers only when JavaScript rendering is required
- Implement efficient caching strategies
- Choose the right scraping approach (API > static HTML > headless browser)
Hidden bandwidth consumers:
- Failed requests that still consume bandwidth
- Redirects (each hop uses bandwidth)
- Compression overhead (gzip/brotli headers)
- DNS and TLS handshakes (minimal but adds up at scale)
Optimization strategies:
Using a bandwidth calculator helps you identify which resources to block. Blocking images and videos alone can reduce bandwidth by 70-90% on media-heavy sites.