WiFi Direct
WiFi Direct is a standard that lets two devices connect over WiFi directly, without a wireless access point or router in between. One device acts as a software access point that the other joins, giving a peer-to-peer link with the range and throughput of WiFi rather than the low bandwidth of Bluetooth. It is commonly used for device-to-device file transfer and for local networking where no infrastructure is available.
How it works
Normally, WiFi devices talk to each other through an access point. WiFi Direct negotiates a peer-to-peer group in which one device takes the role of group owner, effectively a lightweight access point, and other devices connect to it. The result is a direct WiFi link with no external router required.
Because it is WiFi, the link offers much higher throughput and longer range than Bluetooth, which makes it well suited to moving large files or streaming between devices. Support and behavior vary across platforms and hardware, so applications typically use WiFi Direct where it is available and fall back to other transports where it is not.
In a mesh, WiFi Direct usually plays the role of the bulk-data carrier while a lower-power radio handles discovery, because keeping WiFi Direct groups up continuously is more power-intensive than BLE advertising.
Why it matters
WiFi Direct gives phones and other devices a way to exchange large amounts of data directly, with no access point, no internet, and no cost. That is valuable both for convenience, such as sharing files nearby, and for resilience, such as coordinating in a place with no infrastructure.
Paired with a mesh, its throughput lets a network carry files and media that a low-power radio alone could not move.
How it relates to Offline Protocol
Offline Protocol uses WiFi Direct on Android as the high-throughput transport in its multi-transport mesh, DORS, alongside BLE and the internet. BLE handles low-power discovery and small messages; WiFi Direct carries bulk data, including chunked file transfers of up to 100 MiB, when both ends support it. DORS scores the enabled transports continuously and fails over automatically, so a route uses whichever link is best for a given message.
Since SDK v0.28.0, Android 10 and later can form the group without a system dialog: with autoAccept on, devices of the same app find each other through Wi-Fi P2P service discovery and join one group. iPhones have no WiFi Direct API, so on iOS the same transport runs over the Network framework instead, on the local network or AWDL. Since v0.29.0 the Android side also joins the Wi-Fi network it is on, so an Android phone, an iPhone, and a Python host on one network find each other over DNS-SD with no WiFi Direct group.
See peer-to-peer mesh networking for how transports are chosen and combined.
Frequently asked questions
What is the difference between WiFi Direct and Bluetooth?
WiFi Direct offers much higher throughput and longer range, which suits large file transfers, while Bluetooth LE is lower power and better for discovery and small messages. A mesh often uses both: BLE to find peers and WiFi Direct to move bulk data.
Does WiFi Direct need a router or internet?
No. WiFi Direct forms a direct peer-to-peer link between devices, with one device acting as a software access point, so it works with no router, no access point, and no internet.
How does Offline Protocol use WiFi Direct?
As the high-throughput transport in its mesh on Android. It carries bulk data such as chunked file transfers of up to 100 MiB, while BLE handles discovery and small messages, with automatic failover between transports. Since SDK v0.28.0, Android 10 and later can form the group with no system dialog.
