Key facts
- Google's blog post says Fi supports two of America's best 5G cellular networks without naming either.
- Google Fi has operated exclusively on the T-Mobile network in the US for the past few years.
- Network switching is supported only on the Pixel 9, Pixel 10 and Pixel 11 series at launch.
- Other devices will get access to network switching in 2027, Google said.
- Fi must be configured as an eSIM with all non-Fi SIMs disabled for switching to work.
- Super network support is rolling out at no additional cost on Unlimited Premium and Flexible plans.
Google announced a "super network" upgrade for its Fi cell service on November 10, adding support for a second 5G network alongside T-Mobile. The company's blog post says Fi supports "two of America's best 5G cellular networks" but names neither carrier, and a Google spokesperson declined to name the second network when reached for comment.
Google Fi, a mobile virtual network operator, launched in 2015 as Project Fi with support for both T-Mobile and Sprint. It initially worked only on Google's Nexus phones, which switched between networks based on signal strength. After T-Mobile absorbed Sprint, Fi became a single-network service in the US while continuing to switch networks for international travel.
With the upgrade, phones on Fi can move between T-Mobile 5G and the unnamed second network. The rollout carries limits: switching works only on the Pixel 9, Pixel 10 and Pixel 11 series, with other devices to follow in 2027. Fi must also be set up as an eSIM with all non-Fi SIMs disabled, which rules out traditional dual-SIM use. Support is rolling out at no additional cost on the Unlimited Premium and Flexible plans.
Google's Fi FAQ no longer confirms T-Mobile as a network partner, and the company previously highlighted its top prioritization on T-Mobile's towers.