What Is Sumplete?

Sumplete is a pure-logic elimination puzzle. Each row and column of the grid carries a target sum; you delete numbers until what remains adds up exactly, in every direction at once. No guessing loop, no feedback colours — like Sudoku, the grid is fully determined and deduction alone gets you home. The site runs daily puzzles alongside an unlimited mode with grids from cosy to cruel.

The famous part: in March 2023, Scottish developer Daniel Tait — Mathler's creator — asked ChatGPT to design a logic game that didn't already exist, and published what it proposed as Sumplete. Tens of thousands played within days. Then came the correction: reporters and players found the mechanic already existed, in a mobile game called Summer and, further back, in the Kakuro/Cross Sums family that's been in pencil-puzzle books since the 1950s. The AI hadn't invented so much as remembered. Both halves of that story are worth knowing; the puzzle is good either way.

Play it at sumplete.com. Sumplete is its own game by its own makers — NerdleBuddy is not affiliated with it (or with Nerdle); this guide is our independent take.

Scan for forced moves first. A row whose numbers already sum to its target keeps everything; a number larger than its row's remaining target must go. Every deletion constrains a column as it fixes a row, so progress cascades — the same interlocking-constraints pleasure as Kakuro, run in reverse (Kakuro fills cells in; Sumplete crosses them out).

Dailies come in a standard grid and a larger 'master' size, with unlimited play beyond that. It's free in the browser with no account; mobile apps using the name exist, but we couldn't verify any as first-party, so the website is the safe bet.