You cannot upgrade the SSD on a modern MacBook Air.

No. Not at all. Apple started soldering the SSD to the motherboard around 2018, and the M1, M2, and M3 Airs all have permanently attached storage. There are no slots, no replaceable modules.

If you’re looking at a used model older than 2018 (like the 2017 MacBook Air), those actually had a removable SSD — but good luck finding a compatible upgrade that doesn’t cost more than the laptop itself. And even then, the rest of the machine is so outdated that it’s not worth the hassle.

So if you’re buying a MacBook Air today, get the storage you need up front. Future you will not have options. This is not where you save two hundred bucks.