SudokuFang: Learn Sudoku

About this app

SudokuFang — the sudoku that explains every step. Hints don't give away the answer: they name the technique, mark the relevant area, and reveal the reasoning step by step. Import any standard sudoku by photo or by hand for an instant rating and a complete solve path. No ads. No subscription. [Layered Hints] · Optional five-layer reveal: technique, area, candidates, eliminations, full explanation · 70+ techniques, from basic eliminations and pairs to chains, fish and beyond [Analysis Workshop] · Import by camera, by hand, or by paste · Detects no solution, a unique solution, or multiple solutions · Difficulty rating (ER and score) with a technique breakdown · Complete solve path, with the technique, eliminated candidates and placed digit marked at every step · View alternative techniques at any step; long-press a candidate to test a hypothesis · Generate puzzles within a score range · Export the solve as a GIF or a long image [Daily Challenge & Library] · Daily Challenge: the same puzzle worldwide, medal calendar, same-month make-up days · Library: seven difficulty tiers, plus your own grouped collections · All-time and weekly leaderboards; race friends on the same puzzle in a room (online) [Variants] · 20 variants: Killer, Diagonal, Jigsaw, Windoku, Thermo, Kropki, Sandwich, Skyscrapers and more, each with four difficulty levels · Custom rule combinations on boards from 4×4 to 9×9 [Input & Display] · Auto-candidates, 10-color annotations, chain drawing, solve replay · Customizable keypad layout, key placement and gestures · Apple Pencil handwriting on iPad · Over twenty color schemes, plus themes generated from your photos

New • Pencil handwriting: write digits straight into cells with Apple Pencil; small corner digits become candidates; learns your handwriting • Custom rule sudoku: combine rules into a new puzzle, 4×4 to 9×9 • Input area settings: 5 keypad layouts, customizable key placement, Minimal and Full presets • Lock input: lock a digit, Erase or Candidates for continuous entry • Gesture settings: customizable long-press, double-tap, swipe and Apple Pencil actions • Drag to fill: drag a digit key onto a cell to place it • Display settings: candidate highlight modes, board and font size controls, coordinate labels; reorganized color schemes • Help: help center, guided tour and in-context tips • Redesigned home screen with a new Workshop entry Other • Bug fixes

Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.

1. First observed Aug 24, 2026 · 12:21 PM Free