Old Toad wrote:
According to the new MacBook Air spec page it will support external displays as follows:
Display Support
Simultaneously supports full native resolution on the built-in display at 1 billion colors and:
• One external display with up to 6K resolution at 60Hz
• Close the MacBook Air lid to use a second external display with up to 5K resolution at 60Hz
https://discussions.apple.com/content/attachment/fc361db7-b9b2-4d39-8a64-be547d1575f6
That would be for the M3 MacBook Airs.
Apple still sells some new 13" MacBook Airs (the computers are new, but the model isn't). On those, the limit is one external display, whether or not you close the lid.
Something that may not be immediately obvious from the M3 MacBook Air specifications is that the "up to 5K" resolution limit apparently translates into Retina modes of "up to UI looks like 2560x1440" (for which the pixel-doubled internal drawing canvas is a 5K one). If you have a 4K monitor, this means that Retina scaling options intermediate between "UI looks like 2560x1440" and "3840x2160" won't be available.
To connect two external displays to an Apple Silicon MacBook Pro, and run both of them at the same time as the internal screen, in a hardware-supported way, you need a 14" or 16" MBP with a Pro chip or a Max chip.