An open-cockpit kayak will portage just as well as a canoe.
A proper canoe has a yoke, and the weight is carried on your shoulders. A single person of average strength (and a little practice) can carry a large backpack AND a canoe with no assistance.
How do you carry a kayak? It has no yoke to carry on your shoulders. Certainly not on your head. It can be carried on your shoulder, but only for very short distances, and not with a lot of gear. Other than that, two people can carry them with the handles at either end. (But that requires two trips, one for each kayak.)
Unless there is some kind of kayak I have never heard of (very possible), a kayak definitely does not lend itself to portages over a few hundred meters in length.