9×9 Queens puzzles — unlimited practice

A fresh 9×9 board whenever you want one, at any difficulty, with 936 finished 9×9 boards behind this page. It is past the Mini, into the part of the ladder where the argument gets long. Place 9 queens: one in every row, one in every column, one in every colour, and no two touching — corners included. Change the difficulty with the pill beside the board, switch size from the Unlimited tab, and keep going: no daily limit, no streak to protect, no clock you have to beat.

What a 9×9 Queens board asks of you

Nine colours over eighty-one squares. The techniques do not change; the number of places they could apply does. Scanning becomes a skill of its own here — you are hunting for the one row, column or colour that is more constrained than the rest, and there are nine of each to check before you can be sure you picked the right one.

Which technique opens the board is what the difficulty pill beside it really changes. The strategy guide works through each named technique in the order the solver reaches for them, and the hint button on this board names the same ones.

Difficulty at 9×9 is a claim about the reasoning

The label never describes the square count — every board on this page has the same 81 squares. It describes what a board demands before it gives up its first queen, and the two move independently: a 9×9 rated beginner can be a shorter read than a 5×5 rated hard, 56 extra squares and all. The Queens Unlimited hub makes the same case with two real boards side by side.

• Beginner — 180 boards. One region already holds a single square, so the first queen is free and the rest falls to counting rows, columns and colours. That one gift is deliberate: from an empty grid the simplest techniques have nothing to bite on without it.
• Easy — 324 boards. Opens on a colour confined to one row or column. It owns that line, everything else in the line is dead, and the 9×9 comes apart from there.
• Medium — 324 boards. Several of those confinements chained together, each one visible only after the last has been marked off — which across 81 squares means marking is part of the technique, not tidying up after it.
• Hard — 108 boards. Pigeonhole arguments spanning several of the 9 regions at once, plus the exclusion reasoning that rules a square out by showing what it would break.

Medium. Hard at this size is where undercounting arguments start spanning more regions than you can hold at once, and it reads much better once medium is automatic.

Practising at 9×9

Sweep in a fixed order — rows, then columns, then colours — instead of following your eye to the busiest corner. A board this wide punishes hunting and rewards inventory.

Two things hold at every size. A hint never guesses: it finds the next move a person could justify, names the technique, and waits for you to press show me before it marks anything. And boredom means move up a difficulty, not a size — the same reasoning with more squares around it is not new practice. The hub page has the full method.

Every 9×9 board here is provably fair

Each one was checked twice: once for having exactly one solution, and once for being reachable from an empty grid without a single guess. The check reruns over the whole pool before every release, so it covers all 936 9×9 boards rather than the handful anybody happened to play. If you are stuck here, there is a next step and the hint can name it.

Where 9×9 sits

The Daily Max plays 9×9 twice, at medium and then at hard; the Daily Mini never comes this far.

• Daily Mini — three boards a day, 6×6 to 8×8. The one that carries a streak.
• Daily Max — ten boards a day, climbing to 10×10 and finishing harder than the Mini ever gets.
• Archive — every past day, still playable and still scored the same way.
• 8×8 practice — one step down, if 9×9 is currently more search than reasoning.
• 10×10 practice — one step up, once 9×9 at hard has stopped surprising you.

Every Queens board size

• 5×5
• 6×6
• 7×7
• 8×8
• 9×9
• 10×10
• 11×11
• 12×12