What changes on Medium?
Medium 16×16 Sudoku uses the same board and rules as Easy, with fewer starting numbers. Each puzzle has one solution. Look for missing numbers in nearly complete rows, then use the crossing columns and boxes to work out where they belong.
If you would like a refresher before starting, the 16×16 Sudoku page has the full rules with worked examples.
Three scanning tricks to try
-
Number sweep
Pick one number — say 11. Look at every box on the board and ask "could an 11 go here?" If a box already has an 11, skip it. If a box only has one cell where an 11 could fit, write it in. Repeat for every number from 1 to 16.
-
Box-fill
Find a box with only a few empty cells. List its missing numbers and check each gap against its row and column. Place a number when only one possibility remains.
-
Sum to 136
Each completed row, column and box adds to 136. If exactly one cell is empty and the other numbers are correct and add up to 125, the missing number is 11.
How to spot a forced number
A "forced number" is when only one number can go in a cell, no matter how you look at it. Spotting them is the main skill on Medium. Here is the order we recommend: check the row, then the column, then the 4×4 box. If that leaves only one legal number, write it in.
On a 16×16, each cell shares its row, column or box with many other cells. After tapping Auto Notes, look for cells with only one candidate left.
When you place a real number, glance back at every row, column and box that touches it. Cells that had two candidates often drop to one — those are your next moves.
When you get stuck
- ✏️ Tap Auto Notes to fill in the current candidates
- 🔎 Tap Check to make sure every filled cell is still correct
- 💡 Tap Hint to fill one cell (it counts in your stats, but it is okay!)
- ↻ Tap Undo to go back if a guess turned out wrong
Ready for the next step?
When you feel comfortable finding your next move on Medium, give Hard 16×16 Sudoku a try. It leaves more gaps to work through using the same rules.
Frequently asked questions
How long should Medium 16×16 take?
There is no target time to beat. Medium leaves more cells to fill than Easy, so allow yourself time to scan and keep notes. Use Check or Hint whenever you need help.
Can I switch back to Easy?
Of course — just tap the Easy tab at the top of the board. Your Medium puzzle saves automatically.
What changes from Easy to Medium 16×16?
The grid stays 16×16, with numbers 1–16 and sixteen 4×4 boxes. Medium starts with fewer filled cells than Easy, giving you more of the puzzle to solve.
Should I memorise anything?
Not really. Just get used to scanning every row, column and box every time you place a number. After three or four puzzles, the habit becomes automatic.
Try other sudoku games
Different rules, same friendly board. Pick a sibling puzzle to play next.