What is Proxy Server?

Proxy Server is a protective server that stands in your connection between you and the server you are trying to connect. It may have various properties and functions, depending on what the provider offers.

What is a Proxy Server? How does it work? | Gridinsoft

Proxy Server

April 19, 2023

Proxy Server, or simply the proxy, is a synthetic layer between the client device and the server. It may act as a network filter, or as a security shield - depending on the setups.

A Proxy Server is a server that acts as an intermediary between the user and the target server. The client's browser first connects to the proxy server and requests the desired resource located on another server. The Proxy then connects to the target server and retrieves the resource from it or returns it from its cache. Companies use proxies for security, network performance, and access to "remote" resources. Individuals use proxies to anonymize traffic or bypass access restrictions.

Regarding proxies, we usually mean a direct proxy. Let's imagine that we make a request. For example, by trying to go to GitHub and typing the URL, press Enter. The proxy doesn't connect us to GitHub directly but intercepts the connection and updates the content of the request by removing the incoming IP and changing the header. As a result, GitHub assumes that the request came from another computer and sends the data to the proxy server instead of us. The Proxy takes the information from GitHub, checks it, and sends it to our computer.

What do they for?

Proxies add an extra layer of protection to your machine. They can be set up as web filters or firewalls to safeguard your computer from the hazards related to incoming requests. Some people use it for personal purposes, like hiding their location while watching movies online. Companies can use proxies for more serious needs.

Common uses for proxies:

  • Increase network security by encrypting requests;
  • Preventing interception of confidential information;
  • Blocking malicious sites and ads;
  • Caching sites to save traffic;
  • Control the use of the network channel;
  • Domain blocking;
  • Monitoring and logging of web requests;
  • Testing of web resources when entering from different IPs.
When cellular carriers were offering their first services for Internet access from mobile devices, they faced a bottleneck problem. Contemporary mobile devices could not handle the website data since it could be just more significant than the RAM amount on the phone. And things like optimizing the site for mobile devices did not exist then. Cell carriers decided to compress the traffic using proxy servers on their machines. That’s why Internet access on mobile devices was so expensive when it appeared - you were paying an additional sum for a proxy, which was obligatory.

Types of Proxy Servers

There are several types of proxy servers classified by anonymity level, traffic flow, services, applications, IP addresses, and availability. They correspondingly differ in their prices and minimal rent terms. The following are the types of proxy servers.

  • Transparent Proxy is standard proxy servers that do not change user data, leaving it in its "pristine" form. That is, they do not hide the IP address. Transparent Proxy handles all HTTP traffic without the user specifying any settings. Example of use: filtering entertainment websites on an educational network.
  • Anonymous Proxy never passes the client's IP address to the target resource. A good option if you don't want targeted ads tracking you or your location. A high anonymity proxy does not transmit an IP address or personal information and does not even identify itself as a proxy. The IP address changes periodically in the process, allowing for maximum privacy. The TOR browser uses this type of Proxy. Because of the IP changes, it is tough to trace the source of the requests.
  • Distorting Proxy works like an anonymous proxy but transmits a deliberately false IP address. This approach is used to bypass local restrictions on access to content. This is a good choice for people who need to hide their location when accessing the Internet. This type of Proxy can give the impression that you are accessing the Internet from a specific country and allows you to hide your identity and that of the Proxy. Even if you are connected to a proxy, your identity remains safe. However, some Websites automatically block distorting proxies, which can prevent the end-user from accessing the sites they want.
  • Residential Proxy use real (white, static) IP addresses. They look like regular clients to the servers. Residential Proxy is suitable for those who need to verify ads placed on their site so that you can block cookies and suspicious or unwanted ads from competitors or detractors. Such proxies are more reliable than other proxy options. That's why it usually costs more to use them.
  • Data Center Proxy are the exact opposite of the previous proxies. They have IP addresses that are not tied to a real device. Cloud providers have high-speed Internet connections. However, if one server hosts hundreds of proxies, they will all have the same IP address. It is suitable for those who need a quick response time and an inexpensive solution. This option allows you to gather information about a person or organization quickly. They allow users to collect data quickly and inexpensively. At the same time, they do not provide a high level of anonymity, which can put the user's information or identity at risk.
  • Public Proxy are the most insecure and unreliable. They can "crash" anytime and are vulnerable to hacker attacks. Finding lists of free public Proxy is not difficult, but finding a good public proxy is almost impossible. Public proxies are an excellent option for those for whom cost is a significant concern and security and speed are not. However, since they are free and readily available, they are often slow because they are overloaded with free users. Also, using a public proxy puts you at increased risk that your information will be available to other users on the Internet.
  • Private Proxy can only be used by one client at a time and is authenticated before use. It's a more trustworthy variant of a public proxy. A private proxy can be transparent or highly anonymous, like the proxies described above, such as a resident or data center proxy.
  • Shared Proxy is one of the cheapest types of proxy servers. The cost of renting a server is shared between clients who access it simultaneously. This option is good for those who don't have much money and don't need a fast connection. The main advantage of shared proxies is the low cost. But because other users use them, you can get banned from a site because someone else under the same IP has done something wrong.
  • Rotating Proxy for each new client allocates a unique IP address. Therefore, the same IP is not used more than once. A rotating server provides a high level of security and privacy. They are also ideal for users who need to do a lot of continuous web scraping. Rotating proxies allow you to access the same site repeatedly anonymously. However, you need to be careful when choosing such services. Some contain public or shared Proxy and thus can expose your data.
  • Reverse Proxy offers an entirely different approach to proxying. It hides not the client's IP address but the server's IP address to which the request is sent. The tool controls access to the server, limits uncontrolled access to the database, and reduces traffic by caching information. Because they act as another web server that can manage incoming requests, the bandwidth load on your organization will be remarkably reduced. But the drawback of reverse proxies can be the potential exposure of the HTTP server architecture if an intruder can penetrate it.
  • SSL Proxy work on the principle of HTTPS requests - requests between the client and the server are protected by encryption. Since the data is encrypted in both directions, the Proxy hides its existence from both the client and the server. Such proxies are better suited for organizations that need enhanced protection against threats that the SSL protocol detects and blocks. This can help boost its search engine ranking Because Google prefers servers that use the SSL protocol, the SSL proxy used in connection with the website. But the content encrypted on the SSL proxy can not be cached, so when you repeatedly visit Web sites, performance may be lower than otherwise.

Proxy and VPN. What is the difference?

The main difference between a proxy and a VPN is that VPN protects all network traffic. In contrast, a proxy protects only Internet traffic from the browser or applications in which the Proxy is configured. It does not control other connections. A proxy passes requests as an intermediary, while a VPN tunnels all network activity to the operating system level.

Companies use VPN to give employees access to corporate resources without worrying about traffic being intercepted or crammed by the ISP. If he gets the usage history, it will only show that you are connected to a VPN. He won't know anything about the traffic. Despite all the positives, a VPN compared to a proxy also has disadvantages:

  • Bigger price;
  • Slower connection;
  • Larger ping time.

For many tasks, the security level of a VPN may be redundant. However, if you want to mask activity in an application, it's worth considering a proxy server. A proxy can help find out what sites team members are visiting or ensure they have access to sites that block users from your country.

Risks of Using a Proxy Server

Like any other third-party service that operates over the Internet, proxy servers are not without security dangers. Understanding the general risks associated with proxies is essential to decide if they are fit for purpose.

Limited privacy. Although proxy servers hide clients' IP addresses, this does not necessarily extend beyond web requests. Free proxy servers typically operate on insecure networks and use ad-based revenue models. This means that anyone can "listen" to the user's traffic, and the advertisements often contain viruses or other malware that can easily infiltrate the user's device.

Data logging. Proxy servers can store users' web request data with their IP addresses. Some services do not encrypt this information, and some may even sell the data to other parties. It is crucial to always carefully read the terms and conditions before using a proxy server.

Open ports. Since most proxy servers work with open ports, some of them can serve as security vulnerabilities. Open ports also increase security risks by increasing the number of attack vectors in an organization.

How to connect to an existing proxy server?

Usually, a proxy consists of an IP and a port number, separated by semicolons and looks like xxx.xxx.xxx.xxx.xxx:yyyyy where x is the IP and y is the port number. Knowing the Proxy's IP address and the port number won't be challenging to connect. That information is usually sent to you by the Proxy server provider - or your system administrator if you want to use the one handled by your company. First, you need to go to the network settings, then to the proxy section, and then enter the information about the server.


A proxy server usage is justified when hiding or protecting information is necessary. Above, we have reviewed the list of tasks that can be solved with the help of proxies. As we have seen, there are advantages to using proxies:

  • Security and privacy of data on the Internet;
  • Ability to bypass restrictions related to geolocation;
  • The ability to improve network performance;
  • The ability to control access to sites.

But there are also disadvantages:

  • Requests may return slower than direct access;
  • Not all proxies encrypt data. Proxy selection should be made with caution;
  • Free and cheap proxies can be attacked, and as a result, the data can be intercepted by scammers;
  • All information always goes through a third party which can be controlled by anyone

Frequently Asked Questions

What is the best proxy type?
Resident proxies are the best for most applications because they represent the IP addresses of actual physical devices. They look like regular users to all servers and are virtually undetectable. Using a resident proxy makes it easier to gain access to the data. This allows clients to avoid geographic restrictions or masking, a method of manipulation that some websites can use to provide false data to clients connecting through data center proxies.
Is proxy server a firewall?
A firewall and a proxy server are components of network security. They are somewhat similar in restricting or blocking connections to and from your network, but they do so differently. For example, firewalls can block individual ports and programs trying to gain unauthorized access to your computer. At the same time, proxies hide your internal network from the Internet. Therefore, it works like a firewall in the sense that it blocks your network from accessing the Internet by redirecting web requests when necessary.
Is proxy server same as VPN?
There are differences between a proxy and a VPN. While a proxy works with one application or site, a VPN encrypts all your network traffic. Like a proxy, a VPN hides your IP address the first time you visit a site after logging in and replaces it with the VPN provider's IP address. However, only the VPN becomes between you and the website and redirects your Internet data through an encrypted tunnel, keeping your online activity confidential. In contrast, the proxy becomes between you and the ISP. Hence the data remains unencrypted.
Why do hackers use proxy server?
An attacker can use proxy hacking to gain an advantage over or eventually redirect users requesting a landing page to a malicious or fraudulent website. Hackers can also use proxy servers to hide malicious activity online. Proxy servers act as an intermediate between the hacker and the target and ensure the hacker's anonymity online.
Can proxy server steal data?
Using a rogue proxy server puts you at risk of identity theft and other cybercrimes. This is because server owners and web admins have unlimited access to your data. Thus, they can sell your personal information to criminals without your consent. It depends on how the proxy server is configured. However, in a "running" proxy, they can see all textual content (i.e., not encrypted with SSL/TLS) in both directions. So yes, they could easily pick up all the IDs and passwords.