Forward vs Reverse Proxy, Explained with Everyday Examples

A reverse proxy acts for the server. Every visitor arrives at it first, and it sends each request on to one of several servers behind it, a bit like a receptionist directing callers to the right department. From outside, there's only ever one front door. Website owners use reverse proxies to:

• share visitors between several servers, known as load balancing;
• handle the encryption on secure connections, known as TLS termination;
• keep ready-made copies of pages, known as caching, so the servers do less work;
• add an extra layer of security in front of the site.

Well-known examples are Nginx, HAProxy and Cloudflare. As a visitor, you only ever deal with that front door; the servers behind it stay out of sight.

• Forward proxies turn up wherever someone needs a website to see a different IP or location: collecting public data, checking that ads display correctly, tracking search rankings and testing how a site looks from another country.
• Reverse proxies sit in front of websites and apps, spreading visitors across servers, serving cached copies of pages, handling encryption and guarding the entrance.

The two aren't rivals. One connection often uses both at once, your forward proxy at one end and the website's reverse proxy at the other, and nobody notices a thing. Unless you run a website yourself, you'll probably never set up a reverse proxy; you'll just walk through other people's front doors.