How to voice chat in Splatoon 3

The Basics: Settings required for Switch voice chat
First of all, the basic requirement is that you need to connect an earphone with some sort of microphone in order to conduct voice chat on the Nintendo Switch.Alternatively, if you use a dedicated voice chat application, you will need a smartphone, tablet, or other device capable of making calls.
The Switch itself does not have a microphone function, however, earphones with a microphone can be connected through the earphone jack.

Also, unlike PS4/5 and Xbox controllers, the Switch controller does not have an earphone jack.
Because of that, if you want to connect headphones in a way other than into the Switch itself, you will need to purchase a special controller with an earphone jack or use a chat application on your smartphone or tablet.
Regarding Bluetooth Connection
The Switch itself supports audio connections via Bluetooth, but does not support microphone use via Bluetooth (as of September 2022). Because of that, the microphone is not usable with a Bluetooth connection.Voice chat in the “Nintendo Switch online” application
This section describes how to install the “Nintendo Switch Online” application on a smartphone or tablet to make calls with.First, install the “Nintendo Switch Online” app on your smartphone or tablet from the app store.
Click here to install the Nintendo Switch Online app. Appstore
Googleplay



Side note, you must also be a Nintendo Switch Online subscriber to use voice chat. On top of that, accounts under the age of 13 cannot use voice chat.
If the app is not running properly, try updating your smartphone or update the “Nintendo Switch Online” app itself. iOS or older versions of Android might not launch properly.



Selecting “Start” will enable the call on the application.
Use an external chat service such as Discord or Messenger app

Discord is used by many gamers and is the standard for voice chat applications, so we recommend installing it if you want to use voice chat in the future.
Click here to install Discord Appstore
Googleplay
How to use Discord and what to do when you cannot hear the other person’s voice or cannot get audio
Check to see if the person is muted or if volume is set to zero. Discord allows you to mute certain people’s voices or adjust the audio volume, so if you cannot hear a particular person, right-click on the user’s name and check the audio settin[Splatoon 3] What to do if you can’t join or play with your friends.

[Splatoon 3] Communication error, how to fix it, connection issues.
