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.
What is 4th of July Sudoku?
4th of July Sudoku fills a classic sudoku grid with nine Independence Day pictures: the Statue of Liberty, Fireworks, Star, Eagle, Barbecue, Balloon, Sunglasses, Ice Cream and Sparkler. Each picture goes once in every row, column and box. Anything that isn’t about the Fourth, from the three views to how many pictures each level deals, holds for all 21 of our picture games and is set out on Themed Sudoku.
The holiday has a built-in intermission: the cookout winds down in the afternoon, and the fireworks cannot start until the sky is dark. Everyone is full and nobody is ready to go home. That gap is what this board is for: a 4×4 on one phone passed round the picnic table, a 6×6 on the porch for two players and an adviser, and the 9×9 for whoever claimed the hammock.
Why does the sparkler only show up on 9×9?
Each size deals the first pictures in the set: four on 4×4, six on 6×6, all nine on 9×9. So the 4×4 is the ceremony, with the Statue of Liberty, the Fireworks, the Star and the Eagle; the 6×6 adds the party, the Barbecue and the Balloon; and the Sunglasses, the Ice Cream and the Sparkler wait for the full board.
The small board’s four look nothing alike (on Windows, a green statue, a purple square, a yellow star and a brown eagle), which suits young children. For a child new to the rules, start with Sudoku for Kids; once the pictures feel easy, try 4x4 Sudoku or 6x6 Sudoku, where digits take over.
Fireworks or sparkler: how do you tell them apart?
The two firework pictures meet only on 9×9, and on a Windows PC they are nearly twins. The 🎆 Fireworks and the 🎇 Sparkler each come with their own square of night sky, so on the board both are small purple tiles with a burst of light in the middle: fireworks need darkness, and these bring their own. No other pair came close in any of our Windows screenshots, taken at phone size on every board, light and dark.
The difference is a stick. The Fireworks are pink and gold rays thrown out from a centre; the Sparkler is one gold spark on the end of a white wire rising from the bottom-left corner. Look for the white line. That is the Windows drawing; an iPhone or Android phone has its own, and there the pair may look less alike, or more.
The Fireworks are 2 and the Sparkler 9. The keypad under the board shows every picture with its number, even in Pictures view, and the key above the board names them. Notes (pencil marks) are tiny pictures in Pictures view, but each has a fixed place in its square, in number order: a Fireworks note sits top centre, a Sparkler note bottom right.
Where can the sparkler go? A hidden single in a row
The pair meets on this 9×9 Medium board, dealt by the game and shown untouched. Row 1 has no Sparkler yet. Go along its empty squares and ask of each: is there a Sparkler in this square’s column, or in its box? Every yes rules a square out, and when only one is left, the Sparkler takes it, though that square might have room for other pictures. That is a hidden single, found along a row rather than inside a box.
Column 5 and the top-middle box both still have room for a Sparkler, so it is the row that settles R1C5. The tile to watch is the Fireworks at R3C5, two rows below: read it as a Sparkler and R1C5 is ruled out too, leaving row 1 nowhere to put one. The game digs every Medium board for hidden and naked singles to finish; run on this one, its own singles reached the last square, and a separate solver of ours found just one answer.
Every board here has one answer, so a row, column or box still missing a picture always has a square that can take it. If one seems to have none, look for grey: a wrong picture you placed turns grey and counts a mistake. If nothing is grey, something has been misread, and on this board the purple squares are the first suspects.
How is this different from New Year’s Sudoku?
New Year’s Sudoku is the other fireworks board. It shares the Fireworks, the Star, the Balloon and the Sparkler, and its Sparkler is the ninth picture too, so the same pair meets on its 9×9. The rest of its set is midnight in winter (a clock, champagne, a party popper, a calendar and confetti); this one is daylight, charcoal and a bald eagle, and no other game here deals the Statue of Liberty, the Eagle or the Barbecue.
The Sunglasses and the Ice Cream also appear in Summer Sudoku, which covers the whole season rather than its loudest day, with the sun, a beach umbrella, palm trees, waves and shells.