How can I get all the zip codes to auto fill the cities and states

For my job, it is essential to have specific locations of where people are located, significantly if I can narrow it down to city and state. We are only provided with zip codes, and I would really like that it would autofill the state and city so that I don't have to enter those for hundreds of people manually. It would save my team and myself a whole lot of time if they had it set up to autofill like a lot of the other apps do when they fill in the state and city automatically when you type in the zip code.