Gridsum

Every region has a target sum. Swap tiles until every region matches at once. That is Gridsum — a number puzzle built on pure logic. No timer. No lives. No luck. The board is fully knowable and every solution is reachable through arithmetic and planning alone. HOW IT WORKS The grid is divided into colored regions. Each region contains numbered tiles and a target sum. Swap any two tiles and watch the totals shift in real time. Find the arrangement where every region simultaneously hits its target — puzzle solved. Gridsum starts with a simple 2×2 grid and two regions. As difficulty climbs, the challenge deepens: 3×3 and 4×4 grids, irregular region shapes, and tiles that belong to two regions at once — where a single swap changes two totals simultaneously. Every puzzle is solvable through logic. No guessing required. HUNDREDS OF HANDCRAFTED LEVELS Work through the difficulty tiers: Tutorial, Beginner, Apprentice, Intermediate, Advanced, Expert, Veteran, and Pro, Master, and Grandmaster. Each level is rated by move count. Solve within the target — no hints, no resets — to earn a PERFECT badge alongside your stars. Every level tracks your personal best time and move count. See exactly how much you've improved. DAILY CHALLENGE A new arithmetic puzzle drops every day, seeded by the date. Your streak counts any day you play at least one level — the daily challenge or any regular level. Your current streak and best streak are always visible on the home screen. GLOBAL LEADERBOARD Compete with players worldwide across four ranked categories: total stars earned, solving speed, perfect solves, and highest level reached. Set a display name and see exactly where you stand. BUILT FOR FOCUS Dark background. Glowing neon region borders. Clean geometric typography. Gridsum is designed for players who want a clean, distraction-free logic puzzle — no characters, no story, no countdown pressure. Just numbers and logic. Accessibility options: colorblind mode with pattern fills on region borders, reduce motion, and large text. Free to play with ads. A one-time purchase permanently removes all ads — no subscription, no recurring charge. If you enjoy sudoku, KenKen, Wordle, or number puzzles generally, Gridsum gives you something more spatial and strategic to work through. Download for free and start your first streak today.