Wi-Fi calling sidesteps weak cellular networks, but it's not a perfect substitute.
Wi-Fi calling, also called VoWiFi (Voice over Wi-Fi) is a great way to improve sound quality on your Android phone or iPhone during calls. When turned on, it runs your calls (and texts) over your Wi-Fi connection instead of your carrier's cellular network. It works by routing your connection through an IPsec tunnel and ePDG connection (like a VPN service) to your carrier's network. From that point, the data is sent to the device on the other end as usual; that's why both devices don't need to have Wi-Fi calling enabled for the feature to work.
As great as this is, the function has its share of disadvantages that you should know before relying on it. For one, it needs a decent connection to work properly, but Wi-Fi network congestion can hamper that, resulting in choppy audio, lag or even dropped calls. And while Wi-Fi calling is designed to shift over to cellular networks when your phone loses its Wi-Fi connection, this "seamless handover" isn't always the case.
Wi-Fi calling allows you to make and receive calls in areas with little or no cellular coverage. So if there's a cellular dead zone in your home or office where you can't take phone calls or get texts out, it should work fine with Wi-Fi calling. Sometimes, these dead zones aren't your carrier's fault, but are instead caused by the materials used in building construction. Certain window types, metallic coatings, metal beams, masonry walls and thick enough concrete can weaken signal strength, creating dead zones.
Another advantage of Wi-Fi calling is better call quality. Calls made over cellular networks usually have to deal with cellular obstructions, tower congestion and a fluctuating signal, which reduces the call's audio quality (especially if VoLTE isn't available). Wi-Fi calling skips all this because it swaps cellular for more stable and reliable Wi-Fi, enabling noticeably better audio quality (HD voice) on a strong connection.
Rounding up Wi-Fi calling's strong list of pros is how seamless the feature is: you turn it on and forget about it. There's no learning curve because you don't need a different apps for calls, your contacts don't need to use the feature, it doesn't cost more or use up your plan on most carriers and only kicks in when needed on most phones. If your Wi-Fi connection cuts out while talking, it should automatically switch to cellular without dropping the call.
The biggest potential issue with Wi-Fi calling is its dependence on your Wi-Fi network. The quality of Wi-Fi calling is only as good as the network powering it, so if your connection is poor or congested, you're likely going to run into call quality issues. T-Mobile, for example, requires a minimum of 2 Mbps upload and download speeds for Wi-Fi calling to work. Other major carriers don't explicitly mention minimum requirements, but are likely similar. Also, T-Mobile specifically doesn't support Wi-Fi calling over satellite internet or a phone hotspot. Confirm your carrier's Wi-Fi calling requirement before counting on it.
When you move out of Wi-Fi coverage mid-call, your phone should automatically switch to cellular, but this won't be perfect every time. For the handover to work, VoLTE (Voice over LTE) needs to be enabled on your device because legacy cellular networks like 2G and 3G can't handle it. Thankfully, most carriers and phones that support Wi-Fi calling also support VoLTE, so you can turn them on together. But even with this feature, handovers can be bumpy. Emergency calls are another exception. Carriers only route 911 calls over Wi-Fi when there's no cellular network, so if the Wi-Fi signal cuts, there's nothing to hand over the call to.
Wi-Fi calls work on both private and public networks. And like anything that travels over the internet (especially through public Wi-Fi), Wi-Fi calling isn't risk-free. To prevent potential snoopers from spying on your Wi-Fi calls, carriers use an encrypted tunnel between your phone and its network. But that protection depends on your phone's chipmaker and carrier implementing it properly. A 2024 CISPA study revealed that vulnerabilities put the Wi-Fi calls of around 140 million customers in different countries at risk. However, the flaws have been patched, so keeping your device updated is the best way to secure your calls.
Not every carrier supports Wi-Fi calling, so you'll have to check if the feature is available for you first. You'll likely be asked for an emergency address during setup because Wi-Fi calls don't go through a cell tower, making it harder for the operator to locate you the usual way if you call 911. The address you enter tells emergency services where to go if other location data isn't available.
You can use Wi-Fi calling on your iPhone by going to Settings > Cellular. If you have more than one SIM, tap the one you want to use this feature with. Then choose Wi-Fi Calling and toggle on Wi-Fi calling on This iPhone.
For Samsung phones the path is: Settings > Connections > Wi-Fi Calling. On Google Pixels and some other Android devices, the steps are: Settings > Network & internet > SIMs > Operator SIM > Wi-Fi calling.
If you have trouble with weak mobile signals at home or work, Wi-Fi calling is a straightforward way to deal with it. Enable VoLTE if it's not already on by default, and keep your emergency address updated. If the cons of Wi-Fi calling ever outweigh the pros for you, you can easily turn it off.
