@Bruce411I have not used every tool that you mentioned in your post. Technically speaking, each strike for each expiration has its own IV. However, in many IV quotes the tools take weighted averages (ATM strikes carry more weight) to come up with an IV for a given option expiration week. Also, some charts (like at ivolatility.com) use weighted averages across multiple option expirations to come up with an overall IV for a stock across all options expirations. That being said, each of the tools you reference is probably displaying a correct option IV - its just how they are looking at it (strike/expiration specific IV, weighted IV average of a given expiration, or weighted IV average across all expirations).