Reverse proxy
A proxy that sits in front of servers rather than clients, handling incoming requests on their behalf, the opposite direction from the forward proxies used for scraping.
A reverse proxy is the mirror image of everything else in this glossary. A forward proxy stands in front of YOU and conceals your identity from the servers you reach. A reverse proxy stands in front of the SERVERS and fields requests on their behalf, so visitors talk to it rather than to the machines behind it. Same word, opposite direction, chosen by the other party.
Its jobs are all server-side and mostly invisible: distributing load across a pool of backends, terminating TLS so origin machines do not have to, caching responses, compressing them, and keeping origin servers off the public internet entirely. If you have used a CDN, nginx as a front end, or a cloud load balancer, you have used one.
It earns an entry here for a reason beyond terminology, and it is a reason worth understanding if you scrape. When a site challenges you, blocks you or serves you a CAPTCHA, that decision is very often made by the reverse proxy layer rather than by the application behind it. The anti-bot system, the rate limiting, the geographic rules: those typically live at the edge, which is why you can be refused without the site's actual application ever seeing your request.
That also explains a pattern people find odd. A site can be completely unresponsive to one address and perfectly normal from another within the same second, with no apparent logic to it. The edge is making a per-request decision from reputation data and rules, and the decision costs it nothing because nothing behind it was consulted.
The practical distinction to hold onto: if you are configuring a host and port in your own client to change how you appear, that is a forward proxy and it is yours. If a site's infrastructure is deciding whether to serve you, a reverse proxy is part of what decided. You are not buying one of these; you are dealing with one.
Frequently asked questions
Is a CDN a reverse proxy?
Essentially yes, a reverse proxy operating at geographic scale. It sits in front of a site's origin servers, caches and serves content from locations near visitors, terminates TLS and shields the origin from direct traffic. It also commonly carries the anti-bot and rate-limiting rules, which is why a CDN can block you before the site's own application knows you exist.
Can I buy a reverse proxy for scraping?
No, and the question usually signals the two terms have been mixed up. A reverse proxy is infrastructure a site operator deploys in front of their own servers. What you buy for scraping is a forward proxy: residential, datacenter, ISP or mobile. If a provider sells you something described as a reverse proxy for scraping, they are using the word wrongly.
Why does a reverse proxy matter if I am scraping?
Because it is usually what blocks you. Rate limiting, geographic rules, reputation checks and anti-bot challenges generally run at the edge rather than in the application, so a refusal often happens before the site itself is involved. It also explains why the block can appear instant and inconsistent: the decision is cheap and made per request.
What is the difference between a reverse proxy and a load balancer?
They overlap heavily and are frequently the same piece of software. Load balancing, distributing requests across backends, is one of the functions a reverse proxy performs, alongside TLS termination, caching and filtering. A dedicated load balancer may do only the distribution, while a reverse proxy generally does more.
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