Today, Google announced a new feature for its Project Fi cellular service: an always-on VPN. Project Fi's VPN previously was used to encrypt traffic while connecting to a network of free public Wi-Fi hotspots, but now Google will enable the VPN for all your traffic, be it over the LTE service or a Wi-Fi connection.

For now, the always-on VPN will need to be turned on in the Project Fi settings, where the feature is called "Enhanced Network" and labeled a "beta."

"When you enable our enhanced network, all of your mobile and Wi-Fi traffic will be encrypted and securely sent through our virtual private network (VPN) on every network you connect to, so you’ll have the peace of mind of knowing that others can’t see your online activity," Google's blog post says. "That includes Google—our VPN is designed so that your traffic isn’t tied to your Google account or phone number."

Google also claims the "Enhanced network" check box will help users seamlessly transition from a spotty Wi-Fi connection to LTE service. "Our enhanced network automatically detects when your Wi-Fi connection becomes unusable and then fills in those connection gaps with cellular data," Google's blog post reads. "In our testing, we’ve reduced the time without a working connection by up to 40 percent."

Project Fi launched in 2015 as Google's MVNO (Mobile Virtual Network Operator) service. Fi combines service from Sprint, T-Mobile, and US Cellular into a single service. It combines the best features of Google Voice with great international support and sells to consumers under a flexible payment plan that works well for some usage patterns. The big downside is extremely limited device support: thanks to the need for multi-network support, Fi only works with a handful of Android phones.

As always, Project Fi users will know the VPN is active when they see a key icon in the status bar. The "Enhanced network" feature should pop up in the settings later this week for Fi-compatible phones running Android 9 Pie.