A fun project in Python. Think it is far from perfect (maybe better in Java or C++?). The less addresses, the faster it is, of course. It creates a random private key and checks if its address is in the list:

https://preview.redd.it/ij79me6fb2da1.png?width=772&format=png&auto=webp&s=11fdc4c6ebd2705b87d42d4f79e8768618627dfb

370k keys per second in average for 2²⁵⁶ possible combinations.

If god had started that program on my computer during the big bang, it would've tested 0.00000000000000000000062% of all possible keys until today.