This website recently changed postal codes to six digits. If you query from the post office's system, you need to fill in multiple fields of information, and it's not intuitive and time-consuming to find streets from a bunch of drop-down menus. With this website, you can directly paste the address, and it will convert it to 3+3 postal code with just one click. It's much more convenient than going to the post office to look up postal codes. In addition to 3+3 postal code, it also produces 3+2 postal code for you, saving time for looking up postal codes.