Weekly nonogram challenge
Ten new puzzles open every week, one per size and difficulty. Only global records set within the week count.
How the weekly challenge works
Ten new challenge nonograms open every Monday at 00:00 UTC: one 5×5 easy board, plus 10×10, 15×15, and 20×20 in easy, medium, and hard. Each slot has its own puzzle and its own leaderboard.
Challenge puzzles are derived deterministically from the week number, so everyone in the world gets the same boards. Every puzzle is generated to be solvable by line logic alone, all the way to the end — the race is pure deduction speed, no guessing.
Only global records set within the week count, and the board freezes when the week ends. You can browse back to past weeks and replay old puzzles for practice.
No account is needed. Enter a nickname after finishing and your record joins the board; local records always stay on your own device.
Weekly challenge FAQ
When do new challenges open?
Every Monday at 00:00 UTC, all ten slots switch to new puzzles at once. Depending on your time zone that may be Sunday evening or Monday morning — the dates shown use UTC.
Do I have to solve all ten?
No. Every slot has a separate board, so pick the size and difficulty you enjoy. If you are new to nonograms, the 5×5 or 10×10 easy slots are the place to start.
Do the big boards even fit on a phone?
Yes — the 15×15 and 20×20 boards support zooming and panning, and the number clues stay in view as you move around, so they play comfortably on mobile.
Are there boards that force guessing?
No. Every puzzle, challenges included, is verified to reach its unique solution through row and column logic alone.