Futoshiki

Can you slot numbers 1–5 into a grid where rows, columns, and every greater-than sign all have to get along? Pure constraint satisfaction, no math degree needed.

Some puzzles want quick reflexes; Futoshiki wants you to slow down and argue with yourself. The grid is 5x5, numbers 1–5 only, one of each per row and column — standard Sudoku DNA. But scattered between cells are little inequality signs, and they’re not decoration. A 3 sitting left of a 2 violates everything. Once you start treating those < and > symbols like tiny tyrants, the real game begins. I’ll admit, my first few boards were a mess. I’d place a 4 confidently, only to realize the cell to its right had to be bigger, and I’d already burned 5 in that row. The notes mode saved me: tap a selected cell again, and you toggle pencil marks so you can track candidates without committing. That’s where the logic gets crunchy. You’ll spot chains like ‘this must be less than that, which is less than that, so the smallest available number has to go here.’ It feels less like math and more like untangling a knot. What keeps me coming back is the lack of guessing. Every board is solvable by pure deduction, and the interface stays out of your way. No timers, no penalties, just you and the grid. If you’re burned out on speedrun games or want a brain warm-up that doesn’t require a tutorial video, Futoshiki scratches that itch cleanly.

Your goal is to fill cells with numbers 1-5. Each number can occur in row and column only once. You also have to obey inequality signs between cells. Tapping on selected cell toggles notes mode on and off.

Tap a selected cell again to toggle notes mode — pencil in candidates without committing. Start with rows or columns that already have 3+ numbers filled; the remaining slots become obvious fast. Treat each inequality pair as a mini-constraint: the smaller number can’t be 5 and the larger can’t be 1. Look for chains like A < B < C, then assign the smallest possible value to the leftmost open cell. Don’t guess — if stuck, clear a note and re-scan the row and column for a forced single number. The 1 and 5 in each row or column are often pinned down first by inequality signs, so hunt for those extremes.

Q: Is Futoshiki free? A: Yes, it’s a free online logic puzzle with no paywalls or downloads. Q: Can I play Futoshiki on mobile? A: Yes, the HTML5 version works in mobile browsers and responds to touch controls. Q: Do I need to download anything? A: No, just open the page in your browser and start filling cells. Q: Is Futoshiki like Sudoku? A: It shares the no-repeat row/column rule but adds inequality signs between some cells. Q: What does notes mode do? A: Tap a selected cell again to toggle pencil marks so you can track possible numbers. Q: Are the puzzles always solvable without guessing? A: Yes, every board can be solved by pure logical deduction if you read the signs carefully.