Do VPNs Use Data? Here's What You Should Know

Virtual private networks (VPNs) are great tools for keeping your device secure, but VPN apps can use your cellular data to do so. Our VPN usage survey found that security on public Wi-Fi is the number one reason people use a VPN — yet only 39% of Americans actively use one. Whether you need a VPN in a public library, at a coffee shop, or while traveling internationally to access blocked content, understanding how much data your VPN uses can help you stay protected without blowing your data plan.

Mobile data isn't cheap — especially if you go over your limit — so it is important to know how much data you're using, and, more importantly, whether using a VPN will increase the amount of data used. If you're traveling outside of your network, you may also encounter roaming data fees, which can increase your monthly bill.

Choosing the best VPN and the right encryption protocol for your situation will help you control your data usage while keeping your connection adequately secure.

Does a VPN use data?

Yes — VPN apps use additional data, whether you're on a cellular network or Wi-Fi. There's no universal figure for exactly how much, but estimates generally put the overhead at around 5–15% more than you'd use without a VPN. 

The exact amount of data used depends on the encryption protocol in use, the type of activity, and the VPN provider.

Some VPN providers publish estimated data overhead figures, but many don't, so you may not know precisely how much extra data you're consuming until you check your usage or receive your bill. If data usage is a concern, look for a provider that's transparent about this.

If you want to avoid using your cell phone's data plan altogether, connecting to Wi-Fi is the simplest solution. However, keep in mind that some home internet plans also have data caps — a VPN connected to Wi-Fi will still add overhead to your usage. If you consistently exceed your cap, your ISP may throttle your bandwidth, significantly slowing your connection.

Our public Wi-Fi survey found that 69% of internet users connect to public Wi-Fi once a week or more, and nearly half have connected to a network without verifying its legitimacy. If you're regularly using public networks, knowing when and how to run your VPN efficiently matters — both for your security and your data budget.

How much data do VPNs use?

The additional data a VPN uses scales with whatever you're doing online. As a simple example, if you download a 10 MB file over a VPN that adds 10% overhead, that download uses 11 MB instead of 10 MB. That doesn't include the data used to authenticate and connect to the VPN server itself.

For more intensive use, the overhead adds up quickly. Say you're traveling for work and need to access confidential documents through your company's VPN. Signing in to the VPN server uses data. Accessing the files uses data. And throughout, the VPN encrypts your traffic and masks your IP address — all of which requires additional data in the background. Without the VPN, you'd only use data to access the files themselves.

For data-heavy activities like streaming video or downloading large files over public Wi-Fi, the VPN overhead scales proportionally with the content size. Streaming in HD while connected to a VPN will use noticeably more data than browsing text-based websites.

We found that the #1 reason people use VPNs is to secure their internet activity while using public Wi-Fi.

VPN protocols that use less data

VPNs use different encryption protocols, each with different trade-offs between data overhead, speed, and security. When you set up your VPN, you can often choose which protocol to use. Here's how the main options compare:

• WireGuard: The most modern protocol and now the default for most major VPN providers. WireGuard uses a lean codebase, which means lower data overhead and faster speeds than older protocols — without sacrificing security. If your VPN supports it, this is generally the best all-around choice.
• IKEv2/IPSec: A fast, stable protocol that works particularly well on mobile devices because it handles network switching (such as moving from Wi-Fi to cellular) without dropping the connection. Moderate data overhead and strong security.
• OpenVPN (256-bit): One of the most widely supported and thoroughly audited protocols. Highly secure with moderate data overhead. Available in UDP (faster, slightly less reliable) and TCP (slower, more reliable) variants. See how OpenVPN compares to WireGuard.
• L2TP/IPSec (256-bit): An older protocol that offers solid security with moderate data usage. Still supported by many providers but largely superseded by WireGuard and IKEv2 in terms of performance.
• OpenVPN (128-bit): Lower data overhead than 256-bit OpenVPN but also reduced security. Not recommended for sensitive use cases.
• L2TP/IPSec (128-bit): Minimal data usage but also minimal security. Rarely recommended.

For most users, WireGuard offers the best balance of low data overhead and strong security. If your VPN doesn't support WireGuard, IKEv2/IPSec or 256-bit OpenVPN are solid alternatives.

Other ways to use less data with a VPN

Choosing an efficient protocol is one way to reduce data overhead. Here are several other practical steps you can take:

Turn off your VPN when you don't need it

One of the easiest ways to conserve data is to run your VPN only when it's actually needed. You likely need a VPN when accessing work files remotely, using public Wi-Fi, or bypassing regional content restrictions while traveling. You generally don't need it for routine browsing on your home network. Getting into the habit of toggling it on and off can meaningfully reduce your monthly data overhead.

Use split tunneling

Split tunneling lets you route some traffic through the VPN while other traffic accesses the internet directly. For example, you could send work documents over the VPN while your music streaming app continues to work normally. This is one of the most effective ways to reduce unnecessary data overhead without giving up protection where you need it. Many of the best VPNs include split tunneling as a standard feature.

Some of the best VPNs with split tunneling include:

Avoid free VPNs

Free VPNs often show pop-up ads that consume additional data beyond normal VPN overhead. But the data on free VPNs goes beyond ads — our VPN survey found that 48% of VPN users rely on free services, despite many free VPNs logging user data and selling it to third parties. 

For a tool specifically designed to protect your privacy, that's a significant trade-off. A paid VPN is generally a better investment when data efficiency and genuine privacy are both priorities.

Switch to a more efficient protocol

As covered above, switching to WireGuard (if your provider supports it) or IKEv2 can reduce data overhead compared to older protocols like OpenVPN or L2TP. Check your VPN app's settings to see which protocols are available and select one that fits your needs. For a deeper look at how VPNs work and how to get the most out of yours, see our VPN resource center.

Bottom line

Using a VPN adds some data overhead — typically in the range of 5–15% — but that's the cost of encrypting your connection and keeping your online activity private. For most people, the trade-off is well worth it, especially on public Wi-Fi or when accessing sensitive information remotely.

To keep data usage in check, choose a modern protocol like WireGuard, use split tunneling where available, and toggle your VPN off when you don't need it. And if you're using a free VPN, consider switching to a paid option — the privacy benefits are substantially better, and you'll avoid the extra data drain from embedded ads.

Whether you're protecting yourself on public Wi-Fi, accessing work systems, or browsing privately while abroad, the extra data usage is a worthwhile trade-off for the security a VPN provides. We recommend checking out the best VPNs we've tested.

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