The 1921 Census is now available for study at Find My Past. It is quite interesting, but I have noticed that the transcriptions from image to transcript are often somewhat inaccurate, when there is not really any ambiguity in the image. Or maybe I am getting old and pernickety ?
And, disappointingly, to view either image or transcript you have to make a payment each time. You can do it with a credit card, and it all happens remarkably quickly, but if you did a lot of searching it would mount up a great deal. This will put many people off I should think.