Medium Sudoku

Around 38 givens. Singles run out; you start needing pencil marks.

Play medium sudoku

Unlimited boards, generated fresh each time. Nothing here touches your streak. Or play today's daily sudoku — the same grid for everyone, once per day.

What makes a board medium

Difficulty here is the number of givens — the digits already on the grid when you start. These boards are dug down to 38 clues. Fewer givens means fewer places to anchor a deduction, which is what actually makes a grid hard.

Singles carry most of the grid, then stall. Finishing usually needs locked candidates — spotting that a number in a box is confined to one row or column, which clears it from the rest of that line.

No guessing, ever

Every board is built by removing digits one at a time and, after each removal, checking two things: that exactly one solution still exists, and that a logic solver can still reach it without backtracking. A removal that fails either test is put back. So there's never a point where the only way forward is to pick a number and hope — if you're stuck, a deduction exists and you haven't found it yet.

That's a stricter guarantee than "has a unique solution". Plenty of published sudoku have exactly one answer that no human technique will reach.

How this differs from the daily

The daily sudoku is one grid a day, the same for every player, and it feeds your streak, best times and win rate. This page is practice: unlimited boards at one difficulty, none of them recorded. Past dailies stay in the archive.

Other difficulties

  • Easy Sudoku — Around 50 given numbers, and never a move you have to hunt for.
  • Hard Sudoku — 24 to 26 givens, dug as deep as a board can go and still be logical.