It is possible to use the same WhatsApp app on two devices without any web application or third-party software. A special method has to be adopted for this. All the features of WhatsApp will be available on both devices.
First of all, make sure you have the latest beta version of WhatsApp installed on your primary device. If you are using an older version, then it is better to update to the latest version.
On the second smartphone, you need to enable developer options. This should be done from the settings option. On the same device, change the current number to 600 from the Developer Options Smallest Width section. This may reduce font and icon size. But there is nothing to worry about it.
You install the latest version of WhatsApp from the Play Store on the second smartphone. Select the language when launching the WhatsApp app. In the second step, select the Link with your phone option.
You can see the option to scan the QR code in that option. Now you go back to your primary device. After opening WhatsApp there, tap on the overflow option. Then you will get the option to link to the new device.
In the next step, you will get the option of a QR code scanner. From here, just scan the code on the second handset, and you are almost done. After that, WhatsApp will reload for a while on the second smartphone.
After reloading, WhatsApp will be installed on the second smartphone. By adopting this method, you can use the same WhatsApp account on two devices.
WhatsApp will be connected to two devices simultaneously. All the features of WhatsApp, including message calls, can be enjoyed on two devices. If you want to change any issue related to the feature, you can do it from the settings option of WhatsApp.