Sudoku, rebuilt as an arena
Think in colors. Climb the world.
SudoJ4d' gives you the sharpest thinking tool sudoku has ever had — three-color notes — then puts your solve on a world leaderboard that is verified server-side. Free on iPhone, iPad & Android.
The 3-path note system
Hold three ideas at once.
Every cell carries three note layers — red, yellow, green. Sketch one hypothesis in red, hedge a second in yellow, build your best line in green — several digits per layer, all three living side by side on the same grid.
Then the signature move: Validate. One tap commits every single-digit cell of one color — your whole green line snaps into the grid at once. Wrong turn? Undo restores your notes exactly. Quit mid-think? They're still there when you come back.
Watch the background — the green path is about to commit itself, cell by cell.
Daily ranked
One grid.
The whole world.
Every day, one puzzle per difficulty — medium, hard, expert — and everyone on Earth gets the same one. Two free attempts a day, extra runs at 200 J4D', hints locked. Your best score goes up against the planet: world Top 100, daily, weekly, monthly and all-time.
And the board is clean. Every score is recomputed on the server — minimum solve times, full solution check, no client-side tricks. If a score is on the leaderboard, it was earned.
Private challenges
Six characters.
Total war.
Create a challenge, set the clock — 15 minutes to 7 days — and share the 6-character code. Same puzzle for everyone, fastest time wins, and the prize pool grows with the crowd. Rewards are credited automatically after the challenge closes — no claiming needed.
The jade economy
Show up. Get paid.
One green currency — J4D' — and a calendar that pays it. A monthly Season Pass with one level per day, streak bonuses that stack the longer you stay, quick daily quests, and a referral cut that never expires.
Six worlds
Your grid. Your world.
Six full board themes, straight from the game. Tap one — this entire page re-skins live, exactly like your board does.
Also in the shop: number skins, avatar frames, name styles and titles — common to legendary, all bought with J4D' you earn by playing.
Cell 81 of 81