Sudoku Made and maintained by Brian Hamilton and Karan Hamilton.
Brian builds the playable puzzle tools, while Karan helps test clarity, difficulty feel, and the player experience.
Playable puzzles and controls are tested in the browser for rule accuracy, usability, and a clear solving experience. See how we make and test puzzles, our editorial standards, or report a problem.
New Year’s Sudoku: a puzzle against the clock
New Year’s Sudoku puts the last night of the year on a sudoku board. The Fireworks, Clock, Champagne, Party Popper, Balloon, Star, Calendar, Confetti and Sparkler stand in for the digits 1 to 9, in that order, and each goes once in every row, column and box. Whatever the 21 picture games have in common waits on our Themed Sudoku page, which leaves this one free for the night it was made for.
New Year’s Eve is a party with a deadline, and the hours between dinner and midnight go on half-watching the time. A puzzle suits them: it is quiet, it can be dropped the second the countdown starts, and the game keeps your board in the browser for when you come back. When the last picture goes in, it announces “Midnight solved”, whatever the clock on the wall says.
Why is there no confetti on the small boards?
Because the pictures join in order: each size takes the first four, six or nine, so the party fills up as the board grows:
| Board | Who arrives | Numbers |
|---|---|---|
| 4×4 | 🎆 Fireworks, ⏰ Clock, 🍾 Champagne, 🎉 Party Popper | 1–4 |
| 6×6 | adds 🎈 Balloon, ⭐ Star | 5, 6 |
| 9×9 | adds 📅 Calendar, 🎊 Confetti, 🎇 Sparkler | 7, 8, 9 |
Names and numbers match the board’s key. Each size keeps every picture of the size below it.
The ordering produces two details we refuse to apologise for. The Party Popper is on the smallest board, but its Confetti does not land until 9×9. And the Calendar, the page the whole room turns at midnight, waits for the biggest board. The Clock, the Champagne, the Calendar and the Confetti belong to this game alone; the other five also play in at least one of our other picture games.
Is that the Fireworks or the Sparkler?
The same order keeps the set’s twins apart for as long as it can. The Fireworks are tile 1, on every board; the Sparkler is tile 9, on the 9×9 alone. Across our screenshots (every size, both themes, Windows at phone width), theirs was the only pair that came close: Windows draws both as a small purple square of night sky with a burst of light in it.
Look for the solid star. The Sparkler has one, fat and gold, in the middle of its square, ringed by short sparks. The Fireworks have nothing solid at all: an open ring of thin pink and gold lines on a gold stalk, like a dandelion gone to seed. Other phones draw their own emoji, so there the pair may sit closer or further apart. The Party Popper and the Confetti share streamers, not shape: a striped cone against a yellow ball split in two.
Tap a square holding a Fireworks tile and every other Fireworks on the board lights up; no Sparkler does. Or switch the display to Both, which badges every tile with its number: the Fireworks are 1 and the Sparkler is 9, the first and last numbers on the board.
How do you solve a 9×9 picture sudoku? Count down
Treat the board as a countdown. Some squares are ready the moment it is dealt, because their row, column and box hold eight different pictures between them and the ninth is the answer: a naked single. Fill one in and look at the squares it can see. One that had two pictures left may now have one, and another may be waiting on that. Here are three on a real 9×9 Easy board from this game, ending, as a countdown should, on number 1: the Fireworks.
No pencil marks needed: each step is one look along a row, a column and a box. The other everyday move, a picture with one place left in a row, column or box, is a hidden single, which you can see drawn out on the Themed Sudoku page. We counted this board’s answers with a solver of our own, separate from the game’s: there is exactly one.
We dealt 100 9×9 Easy boards from this game: 40 pictures given, 41 squares to fill. At the deal, 12 to 33 of the 41 were ready straight away, as a naked or hidden single (median 20). Filling every ready square, then looking again, finished all 100 in 2 to 7 rounds, 77 of them in three or four. With no wrong picture on the board, some square is always ready.
New Year’s Eve sudoku for kids staying up late
Start them on the small boards. The 4×4 deals only the Fireworks, the Clock, the Champagne and the Party Popper, four pictures no one will mix up, and the 6×6 adds the Balloon and the Star. For the kids negotiating to stay up, a chain of 4×4s makes an honest countdown clock: one more puzzle, then one more, and the Clock on the board is either encouragement or mockery, depending on how the solve is going.
Mistakes show at once (the wrong picture goes grey), which saves a few arguments at eleven at night. Sudoku for Kids is our guide to teaching the rules, and after the holidays our 4x4 Sudoku and 6x6 Sudoku keep the small boards going without the party.
What other holiday sudoku is there?
Christmas Sudoku counts down to the 24th, and this game takes over for midnight on the 31st. Then Winter Sudoku swaps the party for snowflakes, sleds and hot drinks through January and February.
The other fireworks board is 4th of July Sudoku. Four of its pictures are in this set too: the Star, the Balloon, the Fireworks and the Sparkler. There the Sparkler is ninth as well, so the twins meet only on its 9×9. Otherwise it is a summer afternoon with an eagle and a barbecue, where this one is midnight with a clock and a calendar.
And if the resolution is more puzzles, our Daily Sudoku changes at midnight, local time, so the year’s first is ready as soon as the countdown ends: a resolution with the willpower built in. See you in February.