#cloudflare

A practical guide to web unblockers for scraping: how they differ from plain proxies, what problems they solve (and don’t), what to evaluate, and a shortlist of reputable options.

Cloudflare 520 errors are vague by design. This guide explains what a 520 actually means, the most common scraping causes, and a step-by-step debugging flow with resilient retry and proxy patterns.

A web unblocker is more than a proxy: it’s a managed stack (rotation, headers, retries, sometimes rendering) that turns blocked pages into usable HTML. Here’s how they work and how to choose.

Error 520 is Cloudflare’s generic 'unknown origin' failure. Here’s how to diagnose it (vs 403/1020/524) and fix it with TLS hygiene, headers, session handling, retries, and proxy rotation patterns using ProxiesAPI.