These words essentially have the same meaning. They convey the possibility of whether a task/job can be accomplished. However, I know when these words are used in business there is a slight difference. Feasible is used to address whether a job/task can even be attempted. Viable tends to be used to see if an option/job/ task has the ability to be sustainable over a long period of time. The following are examples of how to use both words: Mike: Can we build this bridge by tomorrow? You: This is not feasible because we need more time. Mike: We can keep the company in business by taking out loans. You: That is not a viable option. We will never make a profit that way. I hope this helps. Let me know if you have questions.

Essentially, there is no difference. What is the sentence it is in?