What Is a Reverse Proxy?

The Difference: Forward Proxy vs Reverse Proxy

A forward proxy sits in front of clients (like your browser or an AI agent) and routes their requests to the internet. It hides the client’s IP address from destination servers. When you use ProxyBase, you’re using a forward proxy — your requests go through a residential IP before reaching the target website.

A reverse proxy sits in front of one or more servers and routes incoming client requests to the right backend. It hides the backend servers’ details from clients. Popular reverse proxies include Nginx, HAProxy, Cloudflare, and AWS Application Load Balancer.

What Reverse Proxies Do

• Load balancing: Distribute incoming traffic across multiple backend servers so no single server gets overwhelmed. If one server goes down, the reverse proxy routes around it automatically.
• SSL termination: Handle HTTPS encryption and decryption at the proxy layer so backend servers can focus on application logic. This simplifies certificate management — install the cert once on the reverse proxy, not on every server.
• Caching: Store copies of frequently requested responses and serve them directly from the proxy, reducing load on backend servers and speeding up response times. This is what CDNs like Cloudflare do at global scale.
• Security: Act as a shield between the public internet and your application servers. Filter malicious requests, block DDoS attacks, and hide internal server architecture (IPs, software versions, open ports).
• Compression: Compress responses (gzip, brotli) before sending them to clients, reducing bandwidth costs and page load times.

Common Reverse Proxy Software

• Nginx — the most popular. Handles static file serving, reverse proxying, load balancing, and SSL termination in a single lightweight process.
• HAProxy — focused on high-availability load balancing. Common in large-scale microservice deployments.
• Cloudflare — a global reverse proxy and CDN. Sits between your domain and visitors, absorbing DDoS attacks and caching content at edge locations worldwide.
• AWS ALB / API Gateway — managed reverse proxies in AWS. ALB handles layer 7 HTTP routing; API Gateway handles REST and WebSocket APIs.
• Envoy — a modern L7 proxy used in service meshes (Istio, Consul). Designed for dynamic, cloud-native environments.

When Forward and Reverse Proxies Work Together

In a scraping or AI agent pipeline, you chain both:

Your Agent → Forward Proxy (ProxyBase residential IP) → Internet → Reverse Proxy (Cloudflare/Nginx) → Target Website

The forward proxy hides who you are. The reverse proxy is what you’re hitting — it’s how the target website serves traffic, and it’s often the thing running bot detection. If you build scraping or AI agent infrastructure, you need to understand both.