Sudoku More Daily Puzzles
Try a different daily sudoku variant. Every variant uses the same system — one new puzzle per day, same for everyone, with streaks and sharing.
Daily X-Sudoku: A Free Diagonal Puzzle Every Day
Welcome to the Daily X-Sudoku — a brand-new diagonal-constraint puzzle that appears every day at midnight. Unlike our unlimited X-Sudoku mode, the daily version gives you one puzzle per day that is identical for every player worldwide. It's the same addictive Sudoku logic you love, plus two extra rules — both main diagonals must also contain the digits 1–9 — wrapped inside a shared daily challenge where you can compare times, build streaks and share results spoiler-free.
X-Sudoku — also known as Diagonal Sudoku or Sudoku X — adds a deceptively simple twist to the classic 9×9 puzzle. The two main diagonals of the grid (forming an "X" shape) become additional constraint zones. Our daily version follows the newspaper-puzzle-column tradition: one puzzle per day, getting progressively harder through the week, with modern features like streak tracking, a full archive and instant sharing.
Every day at midnight (local time), a new X-Sudoku puzzle appears. Standard row, column and box rules apply, plus both main diagonals must each contain 1–9 with no repeats. Difficulty follows a weekly cycle: Monday/Tuesday Easy with more givens, Wednesday/Thursday Medium, Friday/Saturday Hard with fewer givens, and Sunday Expert.
✖️ What Makes Daily X-Sudoku Special?
The Daily X-Sudoku merges the social hook of a shared daily puzzle (think Wordle) with the elegant extra dimension of X-Sudoku's diagonal constraints. Every solver faces the same grid, the same givens, the same solution — so comparisons are meaningful when you share your results.
The diagonals act as two additional "hidden groups" that intersect with every row, column and box along their path. Cells at the centre of the grid (especially r5c5, where both diagonals cross) become incredibly constrained. This is what makes X-Sudoku feel tighter and more logically satisfying than standard Sudoku — fewer possibilities per cell, but each deduction carries more weight.
X-Sudoku is one of the oldest Sudoku variants, appearing in Japanese puzzle magazines in the late 1990s. The addition of just two diagonal constraints reduces the total number of valid completed grids from roughly 6.67 × 10²¹ (standard Sudoku) to only about 5.05 × 10¹⁹ — a 99% reduction.
📋 Rules of Daily X-Sudoku
- Row rule — Every row must contain the digits 1–9 exactly once.
- Column rule — Every column must contain the digits 1–9 exactly once.
- Box rule — Every 3×3 box must contain the digits 1–9 exactly once.
- Diagonal rule — Both main diagonals (top-left to bottom-right and top-right to bottom-left) must contain the digits 1–9 exactly once.
Rules 1–3 are identical to classic Sudoku. Rule 4 is the "X" twist — just two extra constraint lines, but they change the entire solving experience.
⭐ Weekly Difficulty Progression
- Monday & Tuesday — Easy — More given digits, straightforward diagonal logic. Great for beginners.
- Wednesday & Thursday — Medium — Fewer givens; you'll need to leverage the diagonals heavily.
- Friday & Saturday — Hard — Sparse clues, advanced techniques like X-Wing and Swordfish along diagonals.
- Sunday — Expert — Minimal givens; every constraint line counts.
Always start at the centre cell (r5c5). It sits on both diagonals and in the centre box, giving it five constraint groups instead of the usual three. If a given appears there, it eliminates that digit from one full row, one column, one box and two diagonals simultaneously.
🧠 Key Strategies for X-Sudoku
- Diagonal scanning — Treat each diagonal like a tenth "row." Scan for missing digits and note pencil marks along the diagonal.
- Diagonal–box intersection — The diagonals pass through several boxes. When a digit is locked to certain cells along a diagonal within a box, it can be eliminated from other cells in that box.
- Centre-cell leverage — The centre cell (r5c5) belongs to five groups. Unique to X-Sudoku, it's the most constrained cell on the board.
- Corner-cell logic — Corner cells (r1c1, r1c9, r9c1, r9c9) belong to a row, a column, a box and a diagonal — four constraint groups.
- Diagonal X-Wing — An X-Wing pattern can form along a diagonal and a row/column, creating powerful eliminations unique to X-Sudoku.
📊 Streaks and Sharing
Your streak counts the consecutive days you've completed the daily X-Sudoku. Solve today's puzzle and the streak grows. Miss a day and it resets, but your best streak is always recorded. Press Share after solving to copy a spoiler-free result card.
📅 The Puzzle Archive
Missed a day? Use the calendar below the puzzle to select a past date and replay that day's X-Sudoku. Archive puzzles don't affect your current streak.
🖨️ Want Unlimited or Printable X-Sudoku?
If one puzzle a day isn't enough, generate unlimited puzzles on our X-Sudoku page. Prefer paper? Download free sheets from our printable sudoku section.
Struggling with today's puzzle? Try solving yesterday's at the same difficulty level first. Use the calendar archive, then return to today's puzzle with renewed technique.
Frequently Asked Questions
Daily X-Sudoku serves one new puzzle every day with diagonal constraints — both main diagonals must also contain 1–9. Every player worldwide gets the same puzzle.
Regular Sudoku uses row, column and box constraints. X-Sudoku adds both main diagonals as additional constraint zones, making each cell along the diagonals more tightly restricted.
Yes! Every visitor sees the same daily X-Sudoku. Compare your time and mistakes with friends.
Yes. Monday/Tuesday Easy, Wednesday/Thursday Medium, Friday/Saturday Hard, Sunday Expert.
Absolutely. Use the calendar below the puzzle to pick a past date. Archive puzzles don't affect your streak.
Yes, 100% free with no sign-up or paywall. Open the page and start immediately.