No ads. No guessing. Just pure-logic variant sudoku.

VariantDoku is built for solvers who want more than one daily grid — a growing library of 1,900+ sudoku variants and zero-givens puzzles, every one verified to have a single solution reachable by logic alone. No ads, ever — free or paid. Plus 450+ classic sudoku in 4x4, 6x6 and 9x9.

WHY SOLVERS STAY
- 1,900+ sudoku variants & zero-givens puzzles: killer cages, thermos, kropki dots, XV, arrows, renban, German whispers, palindromes, diagonals, anti-knight, and more
- 450+ classic sudoku in 4x4, 6x6 and 9x9 — the plain grid when you want it, one tap from Discover
- Every puzzle is logic-checked: one unique solution, no guessing required
- A new daily puzzle, free for everyone — compare solve times on the daily leaderboard
- Home-screen widget keeps today's puzzle one tap away
- Audio narration reads the rules and tutorial steps aloud — listen while you study the grid

LEARN ANY VARIANT
- Step-by-step interactive tutorials for every variant, from your first 4x4 grid to mixed-constraint puzzles
- A guided first-launch experience matches puzzles to your level — you're never thrown into the deep end
- Already sharp? Skip straight to the expert grids

TOOLS THAT RESPECT YOUR SOLVE
- Candidate notes, corner marks, colors, and symbols for advanced solving
- Error checking and gentle hints — only when you ask
- Import puzzle links straight into your Library
- Search and filters by difficulty, grid size, and constraint type
- Streaks and solve history to track your progress
- Dark mode and a calm interface designed for long sessions
- Fully optimized for Android phones and tablets in portrait and landscape

HINTS THAT COACH, NOT ANSWER
- Every hint names the next logical step — Hidden Single, X-Wing, W-Wing, Simple Coloring, Forcing Chain — and highlights the cells it depends on
- It reads the pencil marks you already made and builds on them
- It never reveals a digit that isn't logically deduced; when the logic only rules candidates out, it shows you that instead of handing you a number

THE VARIANTS LIST
Sudoku variants supported: Classic Sudoku, Killer Sudoku, Kropki, XV, Thermo, German Whispers, Renban, Palindrome, Between Lines, Lockout Lines, Region Sum Lines, Arrow Sudoku, Diagonal (Sudoku X), Anti-Knight, Anti-King — plus multi-constraint puzzles that combine several on one board, and zero-givens puzzles solved entirely from the variant rules.

Variant+ unlocks unlimited puzzles, unlimited error checking, and offline Library play. The app stays 100% ad-free — free or paid.

Whether you're learning your first killer cage or chasing your hundredth zero-givens solve, VariantDoku is a calm place to practice and improve.

Terms of Use: https://variantdoku.com/terms

BUILT FOR VARIANT SUDOKU SOLVERS
If you follow Cracking the Cryptic, you already know these puzzles. Paste a SudokuPad, CTC, or f-puzzles link and play it here with full variant rules, pencil marks, and hints.
Your imports stay yours: puzzles are decoded and stored on your device, never uploaded to us. Short links need a single lookup to fetch the puzzle — nothing is saved.

Seven days of killer sudoku in both daily puzzles