The Pros and Cons of Enabling Wi-Fi Calling

Wi-Fi calling, also known as VoWiFi (Voice over Wi-Fi), is a great way to improve the sound quality of your Android phone or iPhone during calls. When enabled, it transmits 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 this point on, data is sent to the device on the other end as usual; this is why Wi-Fi calling does not need to be enabled on both devices for the feature to work.

As great as it is, the feature has its share of drawbacks that you should be aware of before relying on it. On the one hand, it needs a decent connection to work properly, but Wi-Fi network congestion can hamper that, leading to choppy audio, lag, or even dropped calls. And even though Wi-Fi calling is designed to switch to cellular networks when your phone loses its Wi-Fi connection, this “seamless handover” isn’t always the case.

Wi-Fi calling lets you make and receive calls in areas with little or no cellular coverage. So, if there is a cellular dead zone in your home or office where you can’t take phone calls or send text messages, it should work fine with Wi-Fi calling. Sometimes these dead zones are not your carrier’s fault, but rather are caused by the materials used in the construction of the building. Certain types of windows, metal siding, metal beams, masonry walls, and sufficiently thick concrete can weaken signal strength, creating dead zones.

Another benefit of Wi-Fi calling is better call quality. Calls made over cellular networks typically have to deal with cellular obstructions, tower congestion, and fluctuating signal, which reduces the audio quality of the call (especially if VoLTE is not available). Wi-Fi calling ignores all of this because it replaces cellular with more stable and reliable Wi-Fi, allowing noticeably better audio quality (HD voice) over a solid connection.

The list of benefits of Wi-Fi calling is completed by the transparency of the feature: you turn it on and forget it. There’s no learning curve because you don’t need 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 comes in when needed on most phones. If your Wi-Fi connection is interrupted during a conversation, it should automatically switch to cellular without interrupting the call.

The biggest potential problem with Wi-Fi calling is its dependence on your Wi-Fi network. The quality of Wi-Fi calling depends on the quality of the network powering it. Therefore, if your connection is poor or congested, you will likely experience call quality issues. T-Mobile, for example, requires minimum download and upload speeds of 2 Mbps for Wi-Fi calling to work. Other major carriers don’t explicitly list minimum requirements, but are likely similar. Additionally, T-Mobile specifically does not support Wi-Fi calling over satellite Internet or a phone hotspot. Confirm your carrier’s Wi-Fi calling requirements before relying on it.

When you leave Wi-Fi coverage mid-call, your phone should automatically switch to cellular, but it won’t be perfect every time. For the transfer to work, VoLTE (Voice over LTE) must be enabled on your device, as existing cellular networks like 2G and 3G cannot handle it. Luckily, most carriers and phones that support Wi-Fi calling also support VoLTE, so you can enable them together. But even with this feature, transfers can be bumpy. Another exception is emergency calls. Carriers only route 911 calls over Wi-Fi when there is no cellular network, so if the Wi-Fi signal goes out, there is nothing to transfer the call to.

Wi-Fi calling works on private and public networks. And like anything that travels over the Internet (especially over public Wi-Fi), Wi-Fi calling is not without risk. To prevent potential spies from spying on your Wi-Fi calls, carriers use an encrypted tunnel between your phone and its network. But this protection depends on your phone’s chip maker and carrier implementing it correctly. A 2024 CISPA study found that vulnerabilities endanger the Wi-Fi calling of around 140 million customers in different countries. However, the flaws have been fixed, so keeping your device up to date is the best way to secure your calls.

Not all carriers support Wi-Fi calling, so you’ll need to check if the feature is available to 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 carrier to locate you in the usual way if you call 911. The address you enter tells emergency responders 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 multiple SIM cards, tap the one you want to use this feature with. Then choose Wi-Fi calling and activate 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 as follows: Settings > Network & Internet > SIM > Carrier SIM > Wi-Fi calling.

If you’re having trouble with weak mobile signals at home or at work, Wi-Fi calling is an easy way to solve this problem. Enable VoLTE if it’s not already enabled by default and keep your emergency address updated. If the disadvantages of Wi-Fi calling outweigh the benefits for you, you can easily turn it off.