What is a Web Proxy Server and what does it do?

A Web proxy server, also known as proxy (German: Deputy) or also “application level gateway (Wikipedia)”Is a computer that is placed between your computer and the Internet. It intercepts data transfers between you and the service you want to use. Proxy servers do not simply forward data, they open the contents of the data packets and often forward them modified. This is often desired to protect a network (company, organizations). Data that run through a proxy server are differentiated according to different incoming and outgoing ports. An incoming port (e.g. 8080) is forwarded to another port, but not the complete data transfer of a device.

Proxy server connection representation
Proxy server connection representation

“Ports” can be thought of as a virtual direct dial system for data transmission.

Accordingly, there are ports (major selections) where only website data is exchanged, others also transmit communication to FTP servers, etc. Example: Port 80 or 8080 is mostly used for text content on websites, for example. Port 21 usually only for FTP transfers. If communication to a website is blocked, e.g. Because this is only allowed for local IP addresses, proxies can help because you give users a new virtual IP address or identity. But all users of the proxy server use this identity at the same time. This means that you can also access US blocked content via a US proxy server.

While a proxy server actually always opens data packets and forwards them according to specified rules, data is only forwarded through NAT router and unopened.

The ideal application of proxy servers

Proxy servers are very often used in company networks, which means that you can also control and control access to certain content or even ongoing virus checks in the data transmission of users.

The dangers of proxy services

Encrypted websites are also readable and manipulable!

If a user establishes an SSL connection to a website behind a proxy server, the proxy will perform this encryption, but this also means that NO direct encryption takes place between the user and the website. The contents that are exchanged can therefore be read, even manipulated, by the proxy. Example: A bank transfer, which is usually also transmitted via an SSL connection between the user and the bank computer, can be managed via a proxy server so that it can be manipulated consciously and unnoticed even though the connection is apparently secured! This is a typical attack scenario for hackers who use malware to enter a proxy server for the user and from then on communication also takes place via the proxy of the attackers.

Proxies are easy to spot

In addition, website operators can easily recognize the use of proxy servers and thus block the use of them. Conversely, hackers (but also simply lazy hackers with a search software) can find users of proxies and then use them as targeted targets. Proxy users in particular are generally exposed to a significantly higher number of attacks by unknown hackers than users who do not use any of these services. You can find out the real IP address and thus the identity of the user using various methods. While only one internal and inaccessible IP address is assigned to a user in a company network and this is still protected, private users become a worthwhile attack target through your public vpm Internet provider.

Not all data is passed through proxies

Most free proxy servers available on the Internet also do not forward every port, which means that many data services, e.g. E-mails or file sharing are also not supported at all and they either no longer work or you then share the real IP address.

Proxies store websites and content

Proxies can even cache entire user activity or entire websites or content. If the user calls up a page whose content has already been saved on the proxy, this saved or even manipulated website is also delivered to the user without a direct connection to the web server. In companies and organizations, this is used when hundreds of users access the same content from the Internet every day, and it also significantly reduces Internet data transfer. Of course, it also provides partly outdated data, since the proxy server usually only reloads or updates it after a defined period of time. In an attack scenario, however, this can also lead to massive security problems.

Proxies are used in networks for many tasks:

»Protection of clients

Users who are behind a proxy in a "private network" can be protected from the outside world (Internet) by proxies, since content that is sent in both directions can also be checked and possibly blocked.

»Protection of the servers

Servers that should also be available on the Internet are often concealed behind proxies, i.e. ports that are open on the server are translated and then made accessible by other ports on the Internet. In between, all incoming and outgoing data transfers, including hacking attempts, etc. can be logged or automatic actions can be triggered.

»Bandwidth control

In order to find the bandwidth-intensive services or users in a network, proxies can also keep statistics on them in real time and thus identify these users.

»Preparation of data

You can also consciously change data in a different format while it is being called up by a user / server in the network behind the proxy and thus make it readable or importable.

»Content control

All data content that is sent via the proxy can also be checked for content (keywords, keywords, websites, etc.). Accurate statistics and usage activities can be created and evaluated.


Activities can be deliberately recorded and thus also proven. A typical case would be if the use of Facebook in a company were prohibited. The protocols of the proxy server can be used to show exactly who did what and when. Even if the pages would generally offer SSL encryption, this can be “broken open” by the proxy.

»Translations of services

Sometimes it is important to change or translate external services before connecting to an internal service. Since changes to the output data cannot always be made to ensure compatibility. You can usually do this through proxy services.

You have to trust the proxy operator!

When using a proxy, it is very important to trust the owner of the proxy. Why? Even if your data comes to and from the proxy encrypted, the proxy must decrypt it to send it. This means that your private data will be fully disclosed on the proxy server. If you trust the proxy operator 100% then this is not a problem and you gain security. But who knows who operates the proxy servers that can be found on the Internet and even for free? Of course, there are also secret services among the providers, but also hackers, fraudsters or cheated people who do not even know that your own computer is used as a proxy and the true identity of the hackers remains in the dark.

Therefore, if you cannot trust the proxy provider, you are much safer if you do NOT use a proxy instead!

Note: One should mention the difference between a proxy server on the Internet and a router with network address translation (NAT). (Often these are used for small networks or as WLAN routers)

  • A proxy server sends and receives Internet traffic as an intermediary on behalf of users' devices.
  • A NAT router translates IP addresses between the local network (user) and the Internet (public), a single IP address, through which to represent multiple addresses in the local network. A NAT router, such as a WiFi router at home, does very little to protect you online.

Benefits of proxy servers

  • You can also use proxy servers to open / access websites that are often blocked for your own IP address
  • Your identity is protected as long as the proxy operator is trustworthy or the identity of the individual user is not specifically researched.
  • Proxies are very easy to set up.

Disadvantages of proxy servers:

  • Network administrators or website operators can block the use of proxies very easily.
  • An untrustworthy operator or proxy server can pose a much greater threat to your privacy than not using one! Hackers use free proxies to hack victims!
  • The proxy server can always recognize your identity and also save or even manipulate all user activities!

A VPN-Service offers better protection of your own identity. On-line.

Web proxies are a tool to secure the internet connection that you use. Usually you can use Proxy on all devices as well as Windows computers, Macbook, Linux computers or even on a tablet or smartphone. Basically on any device that has an internet browser. This allows you to easily unlock content without installing software or an additional app, and thus also e.g. access YouTube, Facebook, eBay, Twitter or many other websites, even if you are currently in a country where these websites have been blocked (Turkey as an example).

However, the data on access to the proxy server is usually not encrypted, Your own privacy should therefore not be the most important argument for this. It is still possible to view or save your user activity from third parties. Some proxy providers like ZenMate offers to encrypt the data between the user's browser and the proxy service using SSL. This helps with the transfer of the data, but also does not protect against being spied on directly by the proxy operator, and only a small part of the data transfers are carried out via ports 80 or 8080, which are used by the Internet browser, all other applications such as e-mail, FTP or all programs on the operating system generally communicate via other ports and are therefore neither protected nor anonymized! Therefore, local applications are installed as a solution that convert this data traffic and should also lead to the proxy servers in encrypted form. However, the use is limited to a few devices and data manipulation by the operator is still not excluded, not even when using SSL-protected websites!

A VPN Server can reliably protect all data traffic on most devices.

Because at one VPN Service all data sent or received on your own device are encrypted and this data on VPNServer is not opened but only forwarded 1: 1. the user also receives a unique and public IP address (identity) of the VPNAssigned to servers. Incoming traffic can be on VPN-servers are checked like a firewall, but the data packets are not opened for this purpose, only certain ports are blocked or attacks are automatically reacted to and the data transmissions are blocked. Compared to proxy servers, this is a restricted but much more "private" backup of personal data and activities.

VPN Server function
VPN Server function

VPN Protects the entire data traffic of the device

With a VPN- Service can protect the entire network and not just some ports, including cell phones, tablets and even TV. It also protects all applications, such as your web browser, Skype, Facebook app, online poker software, etc. The connection speeds are also much better. A web proxy is a free service that many Internet users use. This places a heavy load on the individual server, which then leads to a slow connection. Streaming services such as Netflix, Hulu, ITV, Rai.TV, BBC iPlayer, Zattoo, Polsat, PRO.TV, ORT, ZDF, France TV and many other channels can only make sense via anyway VPN-Services or paid proxy services are transmitted or received. Also, free web proxy far from have connection stability as one VPN Connection. Lots VPNVendors also have the functions of separating the VPN-Tunnel immediately establishes a new connection and thus uninterrupted streaming of content is guaranteed. It enables you to receive / stream videos online without interruption.

Proxies use shared Internet access

Whoever uses a web proxy will also encounter speed and width restrictions. Because all devices registered at the same time use the same service and Internet access. This means that the inbound forwarding as well as the common Internet connection often have to be distributed among hundreds of users at the same time. Most proxy servers are therefore already limited to maximum bandwidths by the administrators, so that the entire Internet bandwidth of the connections is not blocked. Since freely accessible proxy servers are not operated professionally on the Internet, this is like a bottleneck through which all data must go in and out. Users therefore complain about connection breaks, timeouts or simply difficult access to content via the proxy. At a VPNServer, where data is usually only forwarded from one IP address to another, this is a much smaller computing operation and bandwidth management can also be carried out, which can assure each user of the full bandwidth. The VPN-Vendors quickly recognize through the workloads of the individual servers where restrictions may arise in the future and can expand these resources even before there is a data congestion.


If you are using a free web proxy, I would strongly recommend that you also think about your privacy and security. Better use one VPN-Anbieter & Service. That is much better and safer!