VPN data usage: does VPN work on cellular data?

Anton P. | August 11, 2021

VPN data usage might be a concern for mobile users aiming to preserve their cellular data. Typically, VPNs appear in contexts discussing Wi-Fi or wired connections. However, these privacy-defending tools are just as practical for netizens perusing the internet away from hotspots. One downside is that users might feel unease over the amount of data dedicated to power a VPN. In most cases, VPN data usage won’t be too greedy. For instance, reliable providers will jump through hoops to minimize VPN overhead.

Does VPN work on cellular data?

The short answer is yes; a VPN does work on cellular data in addition to wired or Wi-Fi connections. However, it also takes a portion of your cellular data for its operations. According to tests, the additional consumption might be anywhere from 4% to 20%.

However, VPN data usage is not a simple black and white affair. Several variables govern just how much your cellular data increases:

The infrastructure of the VPN. The VPN data usage can drastically vary due to the encryption protocols applied. For instance, techniques offering more robust data protection could end up swallowing more cellular data.
Your activities. The online actions performed impact the data usage as well. For instance, high-quality Netflix streaming will consume much more cellular data naturally, even without a VPN. When you add the VPN, the consumed data will be even higher.

Can a VPN help overcome data caps?

A VPN is not an almighty tool. Although it will do a lot, data caps are not an area a VPN can help bypass. Your data plan provider will still be able to calculate just how much of your ordered data you have used. Going over these caps can cost you extra fees, or even the simplest tasks will become difficult to perform.

Unfortunately, a VPN is not a workaround for preserving your monthly data allowance.

Encryption overhead explained

When you send or receive data online, everything gets divided into packets. These parcels of data contain the details on its origin and destination. Without a VPN, packets would proceed to their final stop. However, a VPN encrypts the packet and wraps it in a separate packet (with unique headers) to guide it to the VPN server.

Typically, a packet would hold approximately 1,500 bytes, which translates to 1,500 plaintext characters. However, the VPN requires about 20 bytes of the packet. Thus, less data you want to transfer can be put into a single packet. Instead, the information you transmit will end up divided into more packets.

Thus, the VPN data usage increases because more packets are necessary to send your data to its destination.

How do encryption protocols influence VPN data usage?

The general belief is that the more secure a protocol is, the more data it will consume. However, this should not make you go for VPNs using outdated protocols like PPTP. After all, a VPN is a security tool, and you should not compromise its intended purpose.

Here is the rundown of how different VPN protocols will affect VPN data usage:

WireGuard. WireGuard is a modern VPN protocol ready to outperform its competitors. And its benefits speak for themselves: high-speed performance paired with robust security are difficult to dismiss. When it comes to VPN data usage, tools powered by WireGuard seem to consume less mobile data. According to the statistics, the overhead is minimal, ranging from 4% to 5%.
IKEv2/IPSec. This protocol is in a well-deserved second place. Based on various tests, the overhead is nearly 8%. Thus, if a VPN supports IKEv2/IPSec, it should not exhaust too much of your cellular data. In terms of security, it is also an excellent candidate for protecting your digital identity and data.
PPTP. According to calculations, PPTP should impose an over 8% overhead. Furthermore, this protocol no longer excels in other areas crucial for VPNs. For instance, the outdated protocol lacks security, meaning your data could be in danger. Thus, you should avoid VPN products implementing PPTP as their go-to protocol. Some tools might retain it as an available option. However, it should not be the sole possibility.
OpenVPN UDP. This protocol is one of the most secure options available. However, its overhead is over 17%, much higher than WireGuard or IKEv2/IPSec. Nevertheless, it excels in security, and the UDP alternative also helps it consume less cellular data.
OpenVPN TCP. TCP increases the overhead of the OpenVPN protocol. In some cases, it can reach 20%. The bright side is that this protocol is highly secure. However, it might be best for wired or wireless connections due to its high VPN data usage.

According to experts, different key lengths and ciphers have minimal impact on VPN data usage. Of course, a 128-bit key length could burn less cellular data than 256-bit. However, the contrast is not enough to choose a shorter key length as it won’t drastically reduce the mobile data used.

How can you minimize VPN data usage?

There are ways of limiting the amount of data necessary to make your VPN functional.

Choose WireGuard or IKEv2/IPSec protocols. You might feel that you have no control over the protocol a VPN uses. However, we recommend picking a provider that equips WireGuard or IKEv2/IPSec. They impose a minimal overhead, meaning that they won’t burn through your mobile data as quickly.
Enable split tunneling. Split tunneling allows users to decide which activities traverse through the VPN server. Thus, you can set more data-consuming activities to run without the VPN connection. However, please note that you lose the protection a VPN tool offers.
Disable VPN. Instead of split tunneling, you can disconnect from a VPN server to minimize cellular data usage. However, we recommend allowing a VPN to protect your activities around the clock. If you do decide to turn it off, please note that you also abandon the protection it offers.
Connect to Wi-Fi when available. Another simple solution is to connect to Wi-Fi networks nearby. With a VPN, you won’t have to worry about the common issues taunting public Wi-Fi. Thus, it is a solid option, especially when so many locations offer free hotspots.

When it comes to VPN data usage, Atlas VPN tries to be as lightweight as possible. We equip the IKEv2/IPSec protocol and will soon offer WireGuard across all our products. Thus, the overhead you experience should be minimal.