Wi-Fi Direct allows two devices to establish a direct, peer-to-peer wireless connection without requiring internet or wireless router. It is an ideal solution when you want to send files and documents to other device on the go. Zapya is a cross-platform and free file transfer which supports Wi-Fi file transfer, hotspot file transfer and Wifi direct file transfer. If no Wi-Fi network available, you can create a local group via personal hotspot or WiFi direct on the phone, then connect other devices to it and share files between them wirelessly. You can refer to this tutorial to send files from Android to Windows PC or vice versa using Zapya. Today, we will explain how to copy files between Android mobile phones through Wi-Fi Direct using this free file transfer app.
Turn on Wi-Fi on the first Android device. It does not matter when no Wi-Fi network is available. We don’t need to use a Wi-Fi router or network for file sharing. We are doing this to make sure the Zapya file transfer can turn on Wi-Fi direct.

Go to download the app on to both mobile phones from this link.
On the first Android mobile, run Zapya, tap the Transfer button at the bottom to open the Connect to Share screen as below.

Tap Set Wi-Fi options at the lower section. Then switch from WiFi hotspot to WiFi Direct in the WiFi Type section.

Tap OK and return to previous screen. Touch Create Group to allow Zapya setup the WiFi Direct on your mobile phone. You will then get the WiFi Direct network name and password and a QR code below.
Run Zapya app on the second phone. Tap the Scan button at the top right corner on the home screen of this transfer app to open your phone camera. Point your camera towards the QR code displayed on the first phone to scan it and create connection between them. After that you can select files from one mobile and transfer them to the other device over Wi-Fi direct.