MultipeerConnectivity
MultipeerConnectivity is Apple's framework for discovering nearby Apple devices and exchanging messages, streams, and files with them. On iOS it uses infrastructure Wi-Fi, peer-to-peer Wi-Fi, and Bluetooth; on macOS and tvOS, Wi-Fi and Ethernet. Apple has deprecated it and points developers to the Network framework.
How it works
An app advertises a service type, other devices browse for it, and an invited peer joins a session. Apple's documentation says a session supports up to 8 peers, including the local one, and the framework chooses the underlying transport.
It works only between Apple devices: iOS, iPadOS, macOS, tvOS, and visionOS. Android has its own options, such as Google's Nearby Connections, and the two do not interoperate.
Why it matters
For years it was the simplest way to build local multiplayer, file sharing, and nearby collaboration on iPhone and iPad without a server. Apple's framework page now marks it deprecated, and technote TN3213 covers moving to the Network framework, which supports peer-to-peer Wi-Fi and, through the Wi-Fi Aware framework, standard peer-to-peer Wi-Fi.
Its limits shaped many apps: Apple devices only, small sessions, and direct links between peers rather than relay through other devices.
How it relates to Offline Protocol
Offline Protocol connects iPhones and Android phones to each other over Bluetooth LE, which both platforms support, and relays across up to 8 hops, so cross-platform links do not depend on an Apple-only framework.
Messages and groups are encrypted end to end with MLS (RFC 9420). See Wi-Fi Aware for the standard Apple now supports, and mesh networking for how relay works.
Frequently asked questions
Is MultipeerConnectivity deprecated?
Yes. Apple's documentation marks the framework deprecated and tells developers to migrate to the Network framework, and technote TN3213 covers the move.
Does MultipeerConnectivity work with Android?
No. It is an Apple framework for Apple platforms only. Connecting iPhones and Android phones with no network needs a transport both support, such as Bluetooth LE or Wi-Fi Aware, and a protocol on top that both run.
How many peers can a Multipeer session have?
Apple's documentation says sessions support up to 8 peers, including the local peer. Larger groups need several sessions or a different design, such as a mesh that relays through other devices.
