It's iPhone Duo launch day! While many questions have been raised over the device's availability, it has also become clear that many of your favorite apps might not be optimized for the new layout at launch.
For apps to scale seamlessly across the iPhone Duo, they need to be built on the iOS 27.1 software development kit (SDK). This SDK provides the tools required for apps to stretch effectively across the Duo's new 1:4.1 aspect ratio inner screen.
Without using the updated SDK, apps render with varying sizes of black bars across the unused display area, depending on which legacy SDK version they were built on.
For top-tier VPNs, a lack of display compatibility can be frustrating even if it doesn't impact their functionality. We reached out to major providers to find out if your favorite VPNs are compatible on day one.
Which VPNs are compatible?
Which VPNs are fully compatible with the iPhone Duo?
These VPNs offer the best iPhone Duo experience right now. They are fully compatible with both the inner and outer displays, using the full screen area without letterboxing or black sidebars.
IPVanish was among the first VPN providers to announce full compatibility with the new iPhone. Its updated layout brings faster access to its server list and dedicated feature controls on the adjacent panel. For me, this UI is a marked improvement over its regular interface, and demonstrates the benefits the broader display can have.View Deal
ExpressVPN has long been among the simplest VPNs to use. Unsurprisingly, its iPhone Duo layout closely resembles its iPad app, featuring quick-connect toggles and side-by-side protocol customization. If you're after a simple way to have rock-solid security, this is the choice for the Duo. View Deal
CyberGhost has also opted to simply adapt its iPad layout to the new Duo. It's a great option if you're looking for an affordable, beginner-friendly VPN that takes full advantage of the screen real estate. It does sacrifice additional features for the cost, but it's proven to be an effective VPN for streaming and browsing time and time again, securely nonetheless. View Deal
Private Internet Access has a simple layout for anyone on iPhone Duo, but it also brings the deep customizability that any advanced user could want. It's had some serious updates recently, improving its server network and speeds in ways we haven't seen in years. View Deal
Partially compatible VPNs
NordVPN currently runs on the iOS 27.0 SDK, meaning that while it isn't severely unoptimized, you will still see slim black bars around the display edges that aren't present on fully updated apps. That said, it remains our top-rated overall VPN, so if you're willing to overlook the minor visual compromise while an update rolls out, you'll still benefit from top-tier performance.View Deal
Which VPNs aren't compatible?
Which VPNs aren't compatible with the iPhone Duo right now?
These VPNs currently run an SDK older than 27.0, meaning you'll see large black spaces when using the service on both the inner and outer display. This doesn't necessarily impact the performance of the VPN itself, but could become extremely annoying nonetheless.
Mullvad confirmed to TechRadar that it currently has no plans to optimize its app for the iPhone Duo. This means you'll be looking at a condensed version of the app when both folded and unfolded for the time being. We haven't seen this cause any major functionality issues, but it could become increasingly annoying depending on how much you use your VPN. View Deal
Proton VPN, at the time of writing, uses the iOS 26.2 SDK. This means you'll experience the same unoptimized experience as you would with Mullvad. But a Proton representative has confirmed to TechRadar that "Total optimisation and SDK 27.1 will be coming soon when the latest Xcode version is more stable."View Deal