Fox tracks wil be between a quarter and a half dollar in size and coyotes will be between a half dallar and a silver dollar or a little larger. Fox and coyote tracks will be pretty much in a straight line one in front of the other. Most other critters will be seperated left to right. Enter animal tracks in your internet search and you should be able to get good info.
With tracks in snow as the snow melts the tracks will get larger so unless they are fresh it can be a little hard to tell.
AWS