1. Put both Macs on the same network, over Wi‑Fi or Ethernet.

  2. On the Mac you work on, check that Allow Wi‑Fi and Ethernet is on in Settings › Connection. It’s on by default.

  3. In setup, choose Use Wi‑Fi or Ethernet instead at the Cable step. The speed test then recommends a quality for your network.

What to expect

  • The picture is compressed with HEVC, or with H.264 on Macs that can’t decode HEVC in hardware. As setup puts it, “The picture will be softer than over a cable.” It suits documents, chats or a reference window.
  • Highest, the lossless level, needs Thunderbolt. Over a network choose Low, Medium or High.
  • Plug in a Thunderbolt cable and the picture moves over to it by itself, while Prefer Thunderbolt is on.
  • An Ethernet cable straight between the two Macs works the same way.

Only on networks you trust

The picture isn’t encrypted. On a cable only your two Macs are connected; on a network, someone on the same network with the right tools could see it. Use Wi‑Fi and Ethernet at home or on another network you trust, and the cable elsewhere. How your screen travels

If the picture stutters

Wi‑Fi stutters when AirDrop is set to Everyone. What helps