How to Solve Your First Sudoku, Step by Step

Step 1: take a slow look

Before you touch anything, scan the whole board. Notice which rows, columns and boxes already have a lot of values. Those crowded areas are where the easy moves hide, because there are fewer possibilities left to figure out.

Step 2: find a group with one gap

Hunt for any row, column or box that has eight values placed and just one empty cell. The missing value is forced into that gap. This is the safest move in the game, and every time you make one, the board gets a little easier.

Step 3: pick a value and chase it

Choose one value, then look at a single box. Ask where that value can legally go inside the box. Skip any cell that already sees the value in its row or column. If only one cell is left, that is where the value belongs. Repeat this for the same value across other boxes before moving to the next value.

Step 4: use notes when it gets harder

When the obvious moves run out, switch on Notes mode and mark the candidates for each empty cell. Seeing the possibilities written down turns a confusing board into a clear one. A cell that ends up with a single candidate is solved, and a value that fits only one cell in a group belongs there.

Step 5: keep your notes honest

Every time you place a value, it becomes impossible everywhere else in that row, column and box. Remove it from those notes so you never chase an option that no longer exists. Shapedoku can do this cleanup for you automatically, which keeps beginners from making the most common early mistake.

Step 6: slow down when you stall

If you get stuck, do not guess. Refill your notes, pick one group and study it closely. The next move is almost always hiding in plain sight. If you truly cannot find it, a single hint will reveal one correct cell and often restart your momentum.

A simple loop to remember

1. Scan for any group with a single empty cell and fill it.
2. Pick a value and place it wherever it is forced inside a box.
3. Add notes once the easy moves dry up.
4. Solve cells that have only one candidate left.
5. Repeat until the board is complete.

That loop will carry you through any Easy or Medium board. Start gentle, trust the logic, and enjoy the quiet satisfaction of a finished grid. You can play your first puzzle right now in the browser, free and with no account.