Most scraping projects fail not because of the code but because of the IP strategy: the wrong proxy type is chosen, the budget either falls short or is wasted, and the architecture collapses when the target changes. This article turns proxy selection into a systematic decision process.
Step 1: Analyse Your Target
The choice starts with the target. Answer three questions:
- What is the protection level? A simple test: send 50-100 requests from a datacenter IP. If they go through without trouble, the target is tolerant; if you get CAPTCHAs/403s, it is protected.
- Do you need sessions? If there is a login, a cart or a multi-step form, you need sticky sessions.
- Does location matter? If content/pricing varies by region, you need targeting.
Step 2: Deciding on the Type
| Target Profile | Right Type | Budget Impact |
|---|---|---|
| Tolerant (open data, small sites) | Datacenter | Lowest — unlimited traffic |
| Moderately protected (news, listings, catalogues) | Rotating residential | GB-based, moderate |
| Aggressively protected (marketplaces, booking sites) | Residential + city targeting | GB-based, needs planning |
| Huge targets with IPv6 support | IPv6 subnet | One tenth of the cost |
| Social platform content | Mobile (last resort/hybrid) | Port-based, high |
A hybrid architecture is usually the most efficient: listing pages from datacenter, protected detail pages from residential.
Step 3: Rotation Strategy
- Per-request rotation: the default for independent pages.
- Sticky session: for session flows; assign a separate session ID per thread.
- Pace: random delays of 1-5 s; increase volume during the target's night-time hours.
- Retry policy: on a 403/429, do not persist with the same IP; use a new IP plus exponential backoff.
Step 4: Calculate the Cost in Advance
A simple formula so that GB-based plans hold no surprises:
Monthly traffic ≈ number of pages × average page size × (1 + retry rate)
Example: 20,000 pages a day × 0.6 MB (HTML only) × 30 days ≈ 360 GB/month — a volume that belongs in enterprise-plan territory. Not downloading images, accepting gzip and blocking unnecessary resources (blocking images/CSS in a headless browser) reduces traffic by 50-80%.
Step 5: Production Checklist
- I log success rate (2xx), CAPTCHA rate and latency metrics.
- Proxy credentials are in environment variables, not in the code.
- Separate session pools are defined per target.
- robots.txt and the target's terms of use have been reviewed.
- Backup plan: if the primary pool gets blocked, a second type takes over.
Can You Start With Free?
For a prototype, yes: free proxy addresses are ideal for verifying your code's proxy integration. They are not suitable for production scraping, however — volatility, slowness and shared IP reputation sabotage the process. Prototype → free, production → paid pool is the natural flow.