What is a Reverse Proxy and How Does It Work?

What is a Reverse Proxy?

A reverse proxy sits behind a firewall on the private network ensuring that no user has direct access to a web server. It controls web traffic coming from the user. To protect the backend server(s) from any malice or bots a reverse proxy hides the web server’s location and provides its anonymity. It also serves as a load balancer and significantly improves the web server’s (website’s) performance.

How Does a Reverse Proxy Work?

A user on the public network makes a request to a web server. A reverse proxy intercepts the request and examines traffic coming from the user before forwarding it to the web server. Usually, a user does not know that the request is handled by a reverse proxy.


As a reverse proxy acts as a gateway between a user and a source on the private network, it compresses and caches the most frequent requests. Whether a user had already sent a similar request in the past, a reverse proxy checks if the information about this request is cached on the proxy server or not. If yes, a reverse proxy does not pass the request to a web server. It sends the response from the cache instead, thus lessening network traffic. The result is a greater level of network security, better speed, and web server (website) performance.

Benefits of Reverse Proxy

A reverse proxy controls access to the original server on a private network. It enables to:

Increase web server security

A reverse proxy filters the encrypted traffic and does not send it through a firewall unless it is sure that a request does not contain any malice. By blocking traffic from bad actors a reverse proxy protects the backend server from DDoS attacks ensuring its safety.

Cache a commonly requested content

A reverse proxy caches local content improving the speed, a user’s experience, and web server performance.

Distribute network traffic

A reverse proxy is a great load-balancing tool if there are several backend servers on a private network. It ensures that no one server is overloaded. If one of the servers fails, a reverse proxy redirects a request to the remaining ones constituting flawless operation.

Decrypt and encrypt SSL communications

A reverse proxy decrypts all incoming requests and encrypts all outgoing responses to ensure secure data transmission between a user and a web server. In general, secure reverse proxying slows every connection, however, SSL encryption provides a caching mechanism, and the user and the web server reuse previously negotiated security parameters, freeing up valuable resources on the origin server.

Authenticate a user

If a request is made by the same user there is no need to re‑authenticate every time they connect to a web server constituting the better performance.

How to Set Up a Reverse Proxy?

To set up and configure a reverse proxy it is necessary to purchase special hardware and configure specific software. These solutions can be expensive and require IT expertise as the process is complicated.

  • provision of the host with appropriate specifications;
  • configuration of the operating system and a firewall, deciding on which proxy software to use (open-source Nginx, Varnish, HaProxy, Apache);
  • optimization and adjustment of the proxy software for optimal performance (to configure SSL certificate for example);
  • enumeration and configuration of the backend servers in the proxy configuration files;
  • audit logging setting up;
  • configuration of the firewalls in all the backend servers;
  • excessive testing to verify that configurations meet the user’s needs.

How to Use a Reverse Proxy?

Control unmanaged devices

With the rise of the remote-from-home trend employees often use their personal smartphones and tablets to remain productive working off the network. Rare employees install security software on their personal devices. A reverse proxy acting as a single entry point for any unmanaged device protects against data leakage and malware. The web server administrator can configure a web server so it accepts traffic only from a proxy, thus raising the safety level.

Protect sensitive data

As a reverse proxy inspects the encrypted traffic based on policy, it ensures that no sensitive data is accidentally or on purpose uploaded to cloud apps (or a web server) or downloaded to unauthorized endpoints.

Prevent threats

The infected file when left unattended can spread across all cloud apps within the enterprise causing havoc. By preventing the downloading from unmanaged devices (possibly containing malware) a reverse proxy defends cloud apps and web servers.

Control users’ access

The web server administrators can configure a reverse proxy access policy and reroute all traffic through a proxy instead of configuring each server for employees that access network resources. In big enterprises where there are several backend servers, the process is time-consuming.

Combine different websites in a single URL

Sometimes businesses host their shopping carts apps with a third-party service outside their network. Using a reverse proxy, users never know they have been sent to a different URL for payment. A reverse proxy covers it up.

Monitor traffic

A reverse proxy logs any request that goes through it. Thus it is easier to monitor all data going to and from the website or a web server using a reverse proxy.



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store


Cleanest, regularly updated proxy pool available exclusively to you. We are waiting for you — https://bit.ly/3xOIPGL