Sudoku: Number Match Game by Brainium Studios is one of the cleanest sudoku apps on Android: a calm grid, smart pencil marks, and puzzles that always play fair. That scan-and-place loop does not need an install to work, so we built Grid Nine, a free sudoku that runs right here on this page. Real puzzles with exactly one solution, three difficulty levels, and a daily board shared by everyone in the world. No download, no signup. Tap a cell and you are playing.
Play Grid Nine now
Tap a cell, then tap a number. On a keyboard, use the arrows to move and 1 to 9 to fill.
How to play
Fill every row, column and 3x3 box with the digits 1 through 9, no repeats. Select a cell and the board highlights its row, column and box; select a filled cell and every copy of that number lights up, which is where the real scanning happens. The Notes key switches the pad to pencil marks, Erase clears a slip, and you get one hint per puzzle, so spend it well.
The timer starts when you touch the board, and three wrong entries end the round unless you switch the mistake limit off in the footer. Pick Easy, Medium or Hard for a fresh puzzle anytime, or play the Daily: the same board everyone in the world gets today, with a streak that grows each day you finish it. Best times and streaks are saved on your device. Nothing leaves your browser.
How it compares to Sudoku: Number Match Game
Grid Nine keeps the parts of Brainium’s sudoku that matter at the board level. Every puzzle is generated with a solver in the loop, so each one has exactly one solution and is always finishable by logic. You get the same quality-of-life features that make the app pleasant: pencil notes, same-number highlighting, row and column highlighting, a mistake counter you can switch off, and per-difficulty best times. Rounds feel identical because the game is identical: scan, place, watch the board tighten.
The app is still deeper where depth costs money and years of polish. Brainium’s version has an undo stack, unlimited hints that teach the technique behind the move rather than just filling the square, detailed statistics, color themes, and a proper offline app you can open in airplane mode. Its interface is also tuned for long sessions in a way a page embed cannot match, with rotation support and finer control over how notes behave.
Our version is for the moment you want a real puzzle right now, on whatever device is in front of you. If you finish a Hard board here and immediately want another, or you find yourself protecting a two-week daily streak, the full app is the better home for that habit.
Get the full game
Sudoku: Number Match Game is free with ads on Android, and Brainium’s hint system is the best way we know to actually get better at sudoku rather than just finishing one.
Frequently asked questions
Can I play sudoku online for free?
Yes. Grid Nine, the game on this page, is completely free: no ads, no account, no payment, and it runs in any modern browser on phone or desktop. You get unlimited puzzles across easy, medium and hard, plus one daily board. Your times and streak are stored in your browser’s local storage and never sent anywhere.
Is every puzzle actually solvable?
Yes, by construction. Our generator fills a complete valid grid first, then removes numbers only while a solver confirms the board still has exactly one solution. That means no guessing is ever required and there is never more than one correct answer for a cell, on every difficulty.
Is this the Brainium sudoku app?
No. Grid Nine is an original game we built, inspired by what Sudoku: Number Match Game gets right. It is not affiliated with, endorsed by, or connected to Brainium Studios in any way. The download links above point to the official app.
Does it work offline?
Once the page has loaded, the game makes no further network requests, so it keeps working through connection drops. For true offline play, install the Brainium app, which works fully in airplane mode after install.
What is the daily puzzle?
The Daily is one medium-level board generated from today’s date, so every player in the world faces the same puzzle on the same day. Finish it and your streak grows by one; miss a day and it resets. A new board arrives at midnight, and your best daily time is tracked separately from the other difficulties.
