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What it's like switching between networks (and Wi-Fi) on Google Fi

Pixel 2 Google Fi
Pixel 2 Google Fi (Image credit: Android Central)

Typically when you sign up for a phone carrier, you're just getting service from one network. That's not the case with Google Fi (formerly Project Fi), which lets your phone actively switch between T-Mobile, Sprint and US Cellular. It's a big selling point for the service, and when you add in Wi-Fi calling and texting, it's quite the network juggling act.

After using Google Fi for some time, though, it turns out the regular switching between networks isn't all that confusing after all.

Switching between T-Mobile, Sprint, and US Cellular

Project Fi network on the Pixel 2

Google Fi, when paired with a compatible phone like the Pixel 3, is set up to intelligently choose between T-Mobile, Sprint, and US Cellular's networks depending on which one is offering a better signal at the time. We don't really know how Google's deals have been worked out with each carrier or how the phone determines when to choose one network over another — and with a Fi SIM or eSIM in your phone, the "Cellular network settings" go blank, aside from a single toggle to enable mobile data and data roaming (which you wouldn't ever worry about turning off anyway). That means you don't have any control over which network your phone uses, but it's not actually as scary as it first seems.

In our time using the service all around the U.S., we've seen the phone latch onto T-Mobile primarily, typically only moving to Sprint in some rural areas where T-Mobile has weak or no LTE signal to offer. As Sprint has improved its average speeds and reliability over the past couple of years, we've started to see it used more and more as well. You're only likely to see US Cellular in the regions where it actually runs its own network.

The most interesting thing to note is how seamless the transition is between networks when the phone decides to switch. There isn't actually any indication on the phone when it switches, and no matter which network you're on, the phone will always display "Fi Network" in the status bar. If you really want to keep track of the network switching, though, you can download an app like SignalCheck. Most importantly, there isn't any change in the experience that indicates a switch had been made — no delays, no cutoffs, and no slow data.

The network switching is seamless, and simply expands your speeds and coverage.

While there are technically ways to explicitly choose just one network over the others, we wouldn't actually recommend that. Considering how smooth the transition is between networks, there's little reason to bother with manually switching or sticking with one — and it really defeats the purpose of paying what are still above-average per-gigabyte data rates to get access to all three networks.

The one clear downside of this network switching is the lack of simultaneous voice and data when your phone is on the Sprint network — meaning if you receive a call, you won't be able to use data at the same time if your phone happens to be connected to Sprint. This really is the only reason to try and force the phone to one network or another ... and the only annoyance of this opaque network switching.

All in all, it's a win. Google Fi manages all three networks really well, to the point where you can't perceive the changes, and the parts of the country where the networks don't overlap simply give you more room with data than you'd get by going with a single network.

Then you add in Wi-Fi

Pixel 2 Project Fi Wi-Fi calling

Plain old carrier networks aren't the only story here — there's also a significant part of the Google Fi experience that leans on Wi-Fi (hence the name). The first part of this is built-in Wi-Fi calling and texting, which can utilize your current Wi-Fi connection instead of the cellular networks. This only works when your Wi-Fi connection is deemed fast enough for calls (it doesn't require much speed), but it'll seamlessly drop to the cellular network if necessary without any interruption. This works in the built-in Phone dialer and Google Messenger apps.

This means you can call and text no matter where you are, even when out of cellular range, but perhaps the nicest feature about this Wi-Fi calling and texting is that it doesn't require any intervention or settings manipulation on your part. Simply pick up the phone and call or text, and it'll go out over whatever network will handle it best. And because your "Fi Basics" charge covers unlimited talk and texts, you don't have to worry about which way it's routed.

The other part of the Wi-Fi story is the so-called "Wi-Fi assistant" that automatically connects you to open Wi-Fi as you move about — assuming you have a Pixel. If you choose to keep your Wi-Fi turned on at all times and let the Wi-Fi assistant scan for networks (which is enabled by default), your phone will automatically connect to any completely open Wi-Fi network that it finds and is "verified as fast and reliable" by Google.

It will only connect to networks that are completely open — that is, no password, splash page, "click here to connect," or "watch this advertisement to connect" getting in the way. While at first you may think there are plenty of open networks around you, many of them actually require this extra step of a splash page or some kind of authentication that'll keep your Fi phone from connecting. But because you don't have to actively manage it, it's always nice when you look down and see your phone has been saving mobile data by hopping on a coffee shop's free Wi-Fi.

It'll connect to fewer networks than you'd think, but when it does connect, it works well.

When your phone does find a completely open Wi-Fi network that it can connect to, it'll connect and you'll be using it for data instead of the cellular network. You'll also automatically be connected to a Google VPN service, which is completely free and tunnels your connection past the inherently insecure Wi-Fi network through Google's servers to hit the outside Internet. This is good for your own security, and also helps you maintain a consistent data connection. When the connection degrades or you start to leave the area, your phone will hand off back to the cellular network — including any ongoing calls.

Living the multiple network life

So long as you don't try to tinker much and simply trust what the phone and service can do automatically, you'll be satisfied with the network switching and automatic Wi-Fi access in Google Fi. Having open access to T-Mobile, Sprint, and US Cellular means there are few places where you'll be left without a mobile data connection. And in areas with bad speeds from one of the three carriers, there's a good chance the other two can pick up the slack instead. Network redundancy is always a good thing.

In places where you have access to Wi-Fi — be it a known network or an open one out in public — the built-in Wi-Fi calling and texting features, along with the help of the Wi-Fi assistant, will let you keep using your phone in areas with bad mobile networks or just to save you a few dollars a month in data usage. It's simple, and for the most part it works — it's a truly useful part of the Google Fi experience.

Andrew was an Executive Editor, U.S. at Android Central between 2012 and 2020.

14 Comments
  • Honestly, I've considered getting rid of my Pixel 2 and switching to a non-Google phone just so I can stop getting stuck on the Sprint network in Denver, which is a piece of crap. On the light rail and bus, I can tell where I am without looking out the window by whether or not my phone has data. The Sprint network has awful (and numerous) data dead zones, and the only way around it is to force a switch to the T-Mo network. Auto network switching is by far the worst part of being a Fi customer here.
  • Agreed. I was in Colorado a couple weeks ago and one of my friends phones that uses Sprint was atrocious on Sprints network. Barely had any coverage and 4G LTE speeds were poor.
  • I tried Fi for a year. I was mostly on T-mobile and it proved to me that verizon isn't all that it was cracked up to be. But for my use, it proved to be expensive plus, at the time, you needed a pixel which were crap phones. So when T-mobile offered the senior plan at $60.00 per month, 2 lines, all unlimited, I jumped on it and couldn't be happier. Plus, I get the device I want, and my wife gets what she wants.
  • How does all this scanning and switching affect battery life?
  • I tried it for a little bit but since I am on the edge of both Sprint and T-Mobile coverage it was not reliable enough to have consistent signal. Would always try to switch but the signal with both carriers is so spotty here. Hopefully one of them steps it up here soon or they merge because you have to have Verizon or AT&T to be usable here.
  • Been on Fi for a number of months with no problems. Maybe a drop here or there, but more than AT&T before. Can't tell when switch happens. As for the app mentioned, it ain't ready for Q beta as it keeps crashing.
  • Not being able to have voice and data at the same time on Sprint's network has got to be incredibly annoying. So many times I've looked up things while on the phone with someone or just browsing.
  • We live 1500 feet from a Sprint tower and about 6 miles from a TMo tower.. yet Fi always tries to dump us onto Tmo.. no bars and unusable signal. I'm guessing their agreement with Tmo is cheaper or something... So forcing to sprint is quite a common necessity here.
  • The author failed to mention customer service. It's not that great. I had issues with sending MMS from the US to my friends abroad. Also wifi calling and texting in areas with little or no cell signal is significant battery drain because it always looks for cell signal. There are sometimes some areas I visit where Sprint LTE is strong but CDMA voice network weak or non existent and T-Mobile's network unreliable. Sprint already offers to it's subscribers Volte on iPhone, Samsung phones that enables call and data at the same tine.
  • Are the calls in HD voice with Google fi?
  • I switched to Fi when it became available on the Moto G6. The network switching works well until Sprint or T-Mobile isn't available.... which happened more often than not north of Pittsburgh, PA. Yes WiFi network is there but the auto-setup was far too slow taking in excess of 30 seconds. If you're brisk walker, by the time it finally negotiates the WiFi you're already out of range of it. I found that Verizon had the coverage of both AT&T and T-Mobile combined and switched out of Fi 14 days after my service began.
  • The article does not mention that Google has it own Wi-Fi network with more than 2 million hotspots. In my case, since my home ISP is Comcast, I have access to more than 18 million Xfinity hotspots, including hotspots all over my home city, since Comcast pretty much has a monopoly here. Once you have signed into a Wi-Fi network, the credentials are saved and you are automatically connected whenever you are in range of a network hotspot. For example any time I am at or near our hospital complex my phone connects through its Wi-Fi network. I generally use less than 50 cents of mobile data a month, unless I am travelling. When I visited my sister last year, before I signed into her home Wi-Fi, my phone automatically connected to Comcast at her neighbor's house. In addition to the Pixel phones, the Android One Moto X4, the Moto G6 and Moto G7 support Fi shifting. Past phones included the Nexus 6, 5X and 6P and the LG V35 and G7.
  • Incomplete sentence: You're only likely to see US Cellular in .
  • From my 14 month long and growing Fi experience I haven't noticed any switching related problems, bad call quality, zero dropped calls, slow data, or any other issues. I am using a Pixel 2xl so maybe that helps. Really like this phone by the way. Coming from AT&T this is an improvement and I did like AT&T. Have no idea how far which towers are because it doesn't matter to me as it just works perfectly. My data usage dropped nearly 3GB going to Fi from at&t. Current bill is $30 and I'm a heavy user. Guessing because of all the WiFi I have access to in my area. So it all comes down to where you live, work, and play to whether or not Google Fi will be awesome or crap. Just letting you know there is at least one guy on here that loves it.