connect 2 external displays with Mac book air open so I can use as total of three displays

Copied from the specs for the new M3 MacBook Air:

M3

• 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

As you can see above, the M3 can use two external monitors, but only if the lid is closed (clamshell mode).

(BTW, the M2 MacBook Air only supports one external monitor, so the M3 is a bit of an improvement. But you'll notice the resolutions the M3 supports on those external monitors isn't the same on each).

You do have a 14 day full return in the US, so it's your option to return it for a full refund if you're still within that 14 day window.

mdharia wrote:

I have just bought a new macbook air with M3 technology and it wont connect to two external displays without closing laptop.

Which is what it says in the Technical Specifications. Also on the main MacBook Air description page on the Apple site, where Apple emphasized "Support for up to two external displays (with the laptop lid closed)" as being a new feature.

Based on the Technical Specifications of all of the Macs using base M1, M2, and M3 chips, to date, it looks like the base chips support a total of at most two active video outputs, where built-in screens count against the total. The M3 MacBook Air is actually more flexible than the M1 and M2 MacBook Airs. They can only drive a single external display, period – closing the lid doesn't free up an output and allow you to use a second external display.

My older version of MAcbook air which I bought in 2020 works with 2 external displays and open mac making it three displays

Different models, different capabilities. This is why you read Technical Specifications before buying.

M3 MacBook Air (13" or 15" – specs seem to be the same for both)

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

MacBook Air (Retina, 13-inch, 2020) - Technical Specifications

Simultaneously supports full native resolution on the built-in display at millions of colors and: 

• One external 6K display with 6016-by-3384 resolution at 60Hz at millions of colors, or
• One external 5K display with 5120-by-2880 resolution at 60Hz at millions of colors, or
• Up to two external 4K displays with 4096-by-2304 resolution at 60Hz at millions of colors

FYI,

14" and 16" MacBook Pros with the M3 Pro chip can drive as many as two external monitors with the lid open.

14" and 16" MacBook Pros with the M3 Max chip can drive as many as four external monitors with the lid open.

MacBook Pro (14-inch, M3 Pro or M3 Max, Nov 2023) - Technical Specifications

MacBook Pro (16-inch, Nov 2023) - Technical Specifications

14" MacBook Pros with the base M3 chip can only drive one external monitor. There are reports that Apple will release a software update to let them drive a second monitor when the lid is closed (but only when it is closed). 9to5Mac reports that "The feature will work identically to how it works with the new M3 MacBook Air."

MacBook Pro (14-inch, M3, Nov 2023) - Technical Specifications - Apple Support

https://9to5mac.com/2024/03/04/14-inch-m3-macbook-pro-multi-display-support/

(14" MacBook Pros with the base M3 chip are the successors to the 13" MacBook Pros with the base M2 chip.)