What are proxy servers, and how do they work?

When you use a proxy service like SOAX, your device (or client - for example your web browser or a mobile application) sends its internet requests to one of many proxy servers in its network. The proxy server then forwards your requests to the resource you want to access (for example, a website) and sends its response back to your device.

• What is a proxy server?
• What is a proxy server network?
• How do proxy servers work?
• Types of proxy servers

What is a proxy server?

A proxy server is the server that handles your requests to the internet on behalf of the client you are using to connect to the internet on your device. A client is the software that sends the requests to the proxy server, for example, your web browser or a mobile application. 

Note: For simplicity, we will sometimes say that your device sends the request, even if technically it's the client – the software or application you're using on your device – that communicates with the proxy server.

Physically, a proxy server is a computer that is located in a data center or a virtual machine running on a computer within a network. For example, residential proxy servers are housed in data centers, even though their exit nodes are the residential devices that are distributed across various residential locations.

When you are connected to a proxy, your device sends its internet requests to a proxy server. The proxy server you connected to then forwards those requests to the website or service you want to access. Once the website or service receives your request, it will send its response back to the proxy server, which will forward the response back to your device. The proxy server acts as a middleman between your device and the web.

Proxy servers and privacy

Because the proxy server is acting as an intermediary between your device and the internet, the resources you access while connected to a proxy server will generally only see the IP address of your proxy server, rather than your own IP address. This protects your privacy and also allows you to spoof your real location (by connecting to a proxy server that is in a different location). 

There are some circumstances where the website may be able to see your IP address even if you are using a proxy server. This is called an IP address leak, which can undermine the anonymity provided by a proxy server. IP leaks can be caused by a number of factors, such as certain browser behaviors, proxy server misconfigurations, or vulnerabilities in the proxy server itself.

Some websites employ sophisticated antibot solutions to detect proxy servers by identifying IP address leaks. For example, they can check for discrepancies between the IP address reported by the browser and the IP address received by the server.

What is a proxy server network?

When you use a proxy provider’s service, your device sends its internet requests to one of the proxy servers in the provider’s network. You may connect to a random proxy server, or – if you have dedicated proxies – then you may connect to the same server every time. 

A proxy server network is a collection of interconnected proxy servers managed by a proxy provider to provide you with a pool of IP addresses that you can use to route your internet traffic. In the vast majority of cases, each proxy server in the proxy network has its own unique IP address. (The only time they do not, is when a proxy provider uses a white-laveled pool of IP addresses from another proxy provider, in which case it’s possible they would share some IP addresses.)

A proxy network can be deployed in one location, like a data center that houses datacenter proxies, or it can be distributed across multiple locations, as in a residential proxy network where each proxy server has an IP address assigned to a user device in a physical residential location.

Using a network of proxy servers has a number of advantages:

1. Diversity: Having a range of IP addresses from various geographical regions allows you to bypass geo-restrictions and view the web as if you were browsing from another country.
2. Management: You can choose to automatically rotate the proxy server you connect to which helps to prevent the websites you visit from detecting your browsing activity (this is particularly useful when you are scraping a website).
3. Distribution: Having a large number of proxy servers allows the proxy provider to ensure traffic is evenly distributed across the network, which optimizes performance and prevents servers from being overloaded.
4. Redundancy: Multiple proxy servers means that there is no single point of failure in the network, making the service more reliable. If one proxy server has issues, other servers can take over, so the people using the network do not experience any interruptions.
5. IP blacklisting: If an IP address is flagged for misuse (e.g. spamming or malicious activity), the proxy provider can quickly remove or replace the server without affecting the entire network.

How do proxy servers work?

Proxy servers work by receiving your requests and forwarding them to the resource (for example, a website or online service) you want to access, and then receiving the resource’s response and forwarding it back to your device. We often describe this process in terms of making web requests, but proxy servers can handle other kinds of traffic too, such as TCP or UDP traffic.

As your internet traffic is usually encrypted by Transport Layer Security (TLS), proxy servers typically handle encrypted data without seeing the exact content of your requests and responses.

When you connect to a proxy server, your device communicates with it over the internet using standard networking protocols. The client you use to access the web (such as your web browser) generates a request, and instead of sending the request directly to the target website, it sends the request to the proxy server’s IP address and port.

Proxy servers typically follow this process:

1. Configuring the client: Before you can use a proxy to route your web traffic, you must first configure your device to connect to the proxy service. Your device won’t be able to connect to the proxy server until you configure its network settings to point to the proxy’s IP address and port number.
2. Authenticating the proxy: The client (your application) sends an authentication request to the proxy server, including credentials and the target resource address. The proxy server verifies the credentials and checks that it can access the target resource.
3. Initiating the request: The application you use to access the web generates a request. For example: 

   CONNECT cloudflare.com:443 HTTP/1.1
   Host: cloudflare.com:443
   Proxy-Authorization: Basic
   User-Agent: curl/8.7.1
   Proxy-Connection: Keep-Alive
   

4. Routing the request: Your device sends the request to the proxy server’s IP address and port, e.g. 192.168.1.1:8080
5. Network communication: The request travels over the internet to the proxy server. The communication uses standard networking protocols such as Transmission Control Protocol (TCP), which ensures reliable transmission of data.
6. Connection: The proxy server runs software that listens for incoming connections on the specified port. When your device sends a request, it arrives at the proxy server’s IP address and designated port.
7. Accepting the request: The proxy server’s software accepts the incoming connection from your device and reads the data it sent.
   7a. For HTTP proxies, this data includes client credentials and the target address (IP address or DNS name and the port number).
   7b. For SOCKS proxies, the process involves a series of requests and responses: first, the client authenticates with the proxy server, and then it requests a connection to the target resource for TCP traffic or sets up UDP transport.
8. Processing the request: Once the proxy server has received the request, it processes it as needed. This can include logging (recording details of the request), authentication (checking the request is from an authorized user), and filtering (inspecting the request to make sure it complies with security policies or content filters).
9. Forwarding the request: If the request passes all the checks, the proxy server forwards the request to the target website’s server. The target website sees this request as coming from the proxy server, not your original device.

Types of proxy servers

There are different kinds of proxy servers for serving different purposes. You can sort the types of proxy servers in multiple ways, categorizing them by:

• Functionality
• Protocol
• Anonymity
• Deployment
• Application

Types of proxy server by functionality

Forward proxy:

• Definition: A server that sits between a client and the internet, forwarding client requests to the internet and returning the responses.
• Use cases: Accessing restricted content, improving security, and monitoring internet usage.

Learn more about forward proxies →

Reverse proxy:

• Definition: A server that sits between the internet and a web server, handling incoming requests from the internet to the web server.
• Use cases: Load balancing, improving security, and caching content for faster access.

Learn more about reverse proxies →

Types of proxy server by protocol

HTTP proxy:

• Definition: Handles HTTP requests, primarily used for web traffic.
• Use cases: Web browsing, web scraping, and content filtering.

HTTPS proxy:

• Definition: Similar to HTTP proxies but supports HTTPS for encrypted connections.
• Use cases: Secure web browsing, accessing secure sites, and maintaining privacy.

SOCKS proxy:

• Definition: A binary protocol that can handle UDP traffic and is more efficient than a text protocol like HTTP.
• Use cases: Gaming, P2P sharing, and accessing various types of services beyond web traffic.

Learn more about SOCKS proxies →

Types of proxy server by anonymity

Transparent proxy:

• Definition: A transparent proxy, also known as an inline proxy, intercepting proxy, or forced proxy, is a server that intercepts the connection between an end-user or device and the internet. It is called 'transparent' because it does so without modifying the requests and responses.
• Use Cases: Caching and content filtering, allowing network administrators to manage traffic and enforce policies without hiding the client's IP address..

Anonymous proxy:

• Definition: Identifies itself as a proxy server but does not reveal the client's IP address.
• Use Cases: Anonymity while browsing the web, preventing tracking.

Elite/High-Anonymity proxy:

• Definition: Does not identify itself as a proxy and hides the client’s IP address completely.
• Use Cases: Maximum anonymity and privacy.

Types of proxy server by deployment

Residential proxy:

• Definition: Uses IP addresses provided by ISPs to homeowners.
• Use cases: Appears to the websites you visit as regular residential traffic, useful for web scraping, accessing geo-blocked content, and avoiding IP bans.

Datacenter proxy:

• Definition: Uses IP addresses from data centers that aren’t tied to an ISP.
• Use cases: High-speed, large-scale operations like data scraping and bulk access to websites, when detection is less of a concern.

Mobile proxy:

• Definition: Uses IP addresses assigned by mobile carriers, typically rotating through 3G, 4G, or 5G connections.
• Use cases: Appears to the websites you visit as regular mobile traffic, useful for testing mobile apps and websites, accessing geo-restricted mobile content, and avoiding IP bans.

ISP proxy:

• Definition: Uses proxy servers with IP addresses assigned by ISPs to their customers. Similar to residential proxies but with higher reliability and speed.
• Use cases: Combines the legitimacy of residential proxies with the performance of data center proxies, useful for web scraping, accessing geo-restricted content, and avoiding IP bans.

Public proxy:

• Definition: Freely available for public use.
• Use Cases: Temporary or casual use but generally less reliable and secure.

Types of proxy server by application

Private proxy:

• Definition: A proxy server that restricts access to specific users or clients.
• Use cases: Enhanced reliability, security, and performance for specific applications.

Web proxy or CGI proxy:

• Definition: A proxy that you can usually access through web-based interfaces, specifically for accessing websites.
• Use cases: Anonymizing web browsing, bypassing content filters, and accessing geo-restricted content.

Caching proxy:

• Definition: A proxy that stores copies of frequently accessed content to speed up future requests.
• Use cases: Reducing bandwidth usage, speeding up access to frequently visited sites.

Content filtering proxy:

• Definition: A proxy that blocks access to specified content based on rules or policies.
• Use cases: Enforcing organizational policies, blocking harmful or inappropriate content.

Start using proxies with SOAX

At SOAX, we have a huge pool of unique, whitelisted IP addresses in our global network of proxy servers. We provide residential, datacenter, mobile, and ISP proxies directly to data-hungry businesses, and also use those proxies ourselves to power our Web Unblocker and scraper APIs. 

You can subscribe to our three-day trial and get full access to our proxies for just $1.99.