What Is Project Fi, and Is It Worth It?

Google already makes the OS for your smartphone and, for some of us, makes the phone itself. And if you sign up for Project Fi, the tech giant can provide the cellular service for that phone, too.

Project Fi launched in 2015, as an alternate wireless carrier for select Google devices. With Project Fi, Google uses a blend of Wi-Fi and the networks of three carriers to keep you covered, and its pay-only-for-what-you-use approach may appeal to smartphone owners who balk at paying for one unused megabyte of data — provided they’re using an accepted device. And Google’s data plans just became more appealing now that Project Fi caps the amount it will charge you each month.

What network does Project Fi use?

Like other mobile virtual network operators, or MVNOs, Project Fi relies on another carrier’s network to provide cellular coverage. In Project Fi’s case, a trio of carriers are used — Sprint, T-Mobile and regional carrier US Cellular. Google says that Project Fi determines which carrier has the fastest network where you happen to be and connects you to that one. Should you relocate to an area where another carrier partner has better coverage, you’ll be switched over to the better connection.

But cellular coverage is only part of the Project Fi story. Like fellow MVNOs Republic Wireless and TextNow, Project Fi also delivers talk, text and data over Wi-Fi when a wireless network is available. Again, Google promises seamless switching between Wi-Fi and cellular connections. And it’s that reliance on Wi-Fi that allows Project Fi to offer lower monthly bills compared to the major carriers.

What phones can you use with Project Fi?

Phone selection is probably the biggest limitation with Project Fi, though Google is taking steps to improve things. Previously, you could only use Google devices with the wireless service — the Nexus 5X, Nexus 6P, Pixel and Pixel XL and, of course, the Pixel 2 models Google released last fall.

The Moto X4 Android One is also an option for Project Fi customers. (Credit: Tom’s Guide)There’s also a non-Google phone in the mix. The Moto X4 is among the phones that will work on Project Fi. It’s an Android One version of the phone, meaning it’s as close to stock Android as possible. (A version of the X4 that we saw at the IFA trade show in Berlin had built-in support for Amazon’s Alexa assistant, for example; that feature is stripped out of the Android One edition of the X4.) The X4 is available for $399 through Project Fi, which also gives the service a lower cost option if you don’t want to pay up for the Pixel 2.

MORE: Project Fi Showdown: Splurge on the Pixel 2 or Save on the Moto X4?

Google says it limits which devices are compatible with Project Fi because the devices need to be able to support the Project Fi SIM card, which works with multiple carrier networks. Both the Pixel 2 and Pixel 2 XL cost the same if you buy them through Project Fi as they do at Verizon. Of course, getting your Pixel directly from Google ensures that you’ll get software and security updates as soon as they become available.

Project Fi’s appeal lies in the fact that you won’t have to pay for any unused data.

Project Fi lets you transfer your current cellphone number over to its service when you sign up.

What are the best Project Fi plans?

If Project Fi’s phone selection remains restrictive compared to other carriers, at least it keeps plans simple. You’ve got one plan option: Fi Basics, which provides unlimited talk and text (including international texting) for $20 a month.

But what about data? You estimate how much LTE data you’ll use each month, paying $10 for each GB. Let’s say you expect to use 3GB per month. That would tack on another $30 to your bill, meaning you can expect to pay $50 each month. Given Project Fi’s use of Wi-Fi when available, you presumably would use less LTE data than you might with a traditional carrier.

If you want to use another Android phone or — heaven forbid — an iPhone, Project Fi is not for you.

At first glance, that doesn’t compare particularly well to other low-cost carriers. MetroPCS, currently our top choice among discount carriers, offers a 5GB plan for $40 a month — that same $40 buys you just 2GB of data at Project Fi.

But Project Fi’s appeal lies in the fact that you won’t have to pay for any unused data. Project Fi credits you approximately 1 cent for each MB you stay under your allotment. Sticking with our 3GB scenario, should you use just 2.2GB in a month, you’ll get a refund of $8, which will appear as a credit on your next bill.

A newly introduced Bill Protection feature effectively adds unlimited data to Project Fi. The service now caps your monthly bill at $80 a month, or 6GB of data under Google’s $10-per-gigabyte pricing. However, you’re still able to use data once you go over 6GB without your bill increasing. Only when you hit 15GB of data during a month will Google start to slow your data speeds.

You can add additional people to your Project Fi account for another $15 per line. Everyone on the account draws from the same pool of LTE data, so a family of four that uses 9.5GB a month would pay $160, which is what T-Mobile charges that same family for unlimited data. Bill Protection works on multiline accounts, too, though the cap varies depending on how many lines of data you have.

What special features does Project Fi offer?

Besides rebates on unused data, Project Fi customers are able to use their phones as a wireless hotspot for no additional cost, though any data they use comes out of their monthly allotment.

Project Fi’s real special feature should appeal to international travelers: You’re able to draw from your regular pool of data in 135 countries, without having to pay any roaming fees. To put that in context, T-Mobile lets you use unlimited data when traveling in 140 countries, but it severely limits your speed. Verizon charges you $5 to $10 per day depending on where you’re traveling to use your data plan overseas.

As noted above, unlimited international texting is included with every plan. Phone calls in 135 countries will cost you 20 cents a minute over cellular connections; rates vary for Wi-Fi calls.

Project Fi also offers a referral program, where you get a $20 credit for any friend or relative who becomes a Fi subscriber and stays active for 30 days, including paying for two months of service. You can enjoy up to 10 referral credits, which translates to $200 if you’re particularly persuasive.

What do customers say about Project Fi?

Reviews of Project Fi posted by the service’s users in the Project Fi app are a love-fest for Google’s wireless service. Project Fi gets an average rating of 4.6 out of 5, with more than 80 percent of customers posting 5-star reviews. Customers like paying only for the data they use and the lower monthly bills. The few complaints on the Project Fi app concern call quality.

MORE: 5 Sneaky Ways Your Wireless Carrier Is Ripping You Off

That pretty much squares with the wider perception of Project Fi, which has won the Readers’ Choice Award at PC Mag for two years running. Other reviews at Computerworld and Forbes are similarly glowing, praising Project Fi’s customer service and simplified billing. Those reviews do acknowledge the limitation on supported phones, and the Forbes reviewer suggested that heavy data users won’t get much bill satisfaction from Project Fi.

We reviewed Project Fi and found that it delivered a top-rate customer experience with reliable performance.

The Bottom Line

There are some clear advantages to Project Fi, from the straightforward billing to the monthly credits for unused data. Bill Protection makes Google’s service even more appealing for heavy-data users. If you prefer Google’s Pixel phones, the service is a no-brainer, and international travelers will love the convenience of using their regular data plan to stay connected on the go.

If the Pixel doesn’t appeal to you, though, Project Fi’s many benefits will be out of reach. Other carriers also offer more aggressively priced data plans, though Bill Protection makes Project Fi more competitive. You may not reap Project Fi’s benefits if you’re not around Wi-Fi as much, though. That said, fans of Google devices will find plenty to like about Project Fi.