By the time of seventh street, you are at the showdown you have a pretty good idea of what you have. If you don't, you should go over your seven card stud poker seventh street strategy and basic onlne poker strategy again. You should know what everyone around the online poker table has. Whether it is the best hand or not. You know who has folded and who hasn't. If you can't piece all the clues together than maybe you need more online poker training.
Having come this far, most online poker players won't fold at seventh street unless the raise is massive and they are clearly beat. This is bad seven card stud seventh street strategy.
If you’ve missed your draw then check or if someone has bet you have to fold.
If you think they might be bluffing, raise and see what they do. Them simply calling is the biggest tell there is in online poker.