If the new ssd will hold the used contents of the HDD, a clone is possible.
I have done this to good effect on many intel based laptops, but not a mac so there might be some issues.
Best to google the make/model of the laptop and ssd. If for no other reason to see how to physically do the swap and what any detailed specs might be.
I like the free Samsung ssd migration aid for their devices.
Other ssd vendors may have similar utilities.