Easy Killer Sudoku
Easy here is measured rather than asserted. Every board is solved the way a person solves one before it is offered, and it only reaches this page if nothing harder than reading a cage total and filling a cell that has one candidate left was ever needed.
More cages, not fewer
A search for killer sudoku easy is usually a search for a board that does not stall. The intuition people bring with them is that an easy puzzle has more given away and a hard one less, which is right, but the way it shows up on a caged grid runs backwards from what you would expect.
Difficulty cannot be carried by blanks here, because every cell is blank on every board. It is carried by cages, and each cage is one more total stated outright. Add cages and you add information. So an easy killer grid is a crowded one: boards on this page carry around fifty to seventy separate cages, against roughly thirty-five on the expert page. Smaller outlines, more of them, and that difference alone is most of what makes the puzzle gentle.
The cage of one cell
Push that far enough and you arrive at the single-cell cage, an outline drawn round one square with a total in its corner. A total over one cell is that digit. It is a given wearing a different hat, and easy boards are full of them: more often than not, over half the cages on a board here are single cells, which is to say the grid quietly hands you twenty, forty, sometimes sixty digits before you have reasoned about anything at all.
That is the honest description of what easy means on a killer grid, and it is worth having so that the step up to medium does not feel arbitrary when you take it. None of the rules changed. The board simply stopped telling you as much.
The two-cell cages worth learning first
Cages of two cells are where this puzzle is learned, because a pair of different digits from 1 to 9 can only reach a given total in so many ways. Four totals leave no choice whatsoever: 3 is 1 and 2, 4 is 1 and 3, 16 is 7 and 9, 17 is 8 and 9. Four more leave exactly two options, at 5, 6, 14 and 15. Learn those eight and a good part of an easy board falls out on the first pass.
The rest still narrow things usefully. A two-cell total of 9 has four possibilities, which sounds unhelpful until you notice that none of them contains a 9, since a 9 would need a 0 beside it. Every two-cell cage totalling under 10 throws the largest digits straight out of both its cells, and that is often more useful than knowing the pair.
Where to start on the board above
Find the smallest and the largest totals first and fill the cages that name themselves. Then look along the rows and columns those digits sit in, because a placed digit is worth far more than a read total: it eliminates in three directions at once. On an easy board that cascade usually runs a long way before it stops, and when it does stop, the next move is nearly always another cage you had not read yet rather than a technique you have not learned.