Number Mosaic

The basics

A clue of 3 1 in a line of ten means three filled cells in a row, at least one empty cell, then one more filled cell; a line with no filled cells shows 0. Work the lines whose clues are already forced, mark the cells you know are empty, and come back to the long lines once their neighbours have narrowed them. Fill paints a filled cell, Mark crosses a cell out as empty, and a tap on a filled cell erases it. Marks are notes: they never count as a mistake and they are not part of the win test, so crossing out is free information for you. Press and drag along a row or a column to paint a whole run at once; one press-release is one stroke and one undo step. Hint looks at the cells you have actually filled, runs the same line-by-line narrowing a person would, and reveals one cell that is already forced — it does not read the saved picture. When your filled cells contradict the clues it says so and asks you to undo or clear them. Check counts the cells that disagree with the picture without saying which ones. Every puzzle was generated and verified offline: repeated row and column narrowing fills the entire grid from the clues alone, so no puzzle ever needs a guess and every solution is unique. Stars: three for a solve with no hint, two with one hint, one with more. The timer starts on your first paint; your best time and stars per puzzle stay in this browser only. Puzzles are 5×5 (easy), 10×10 (medium) and 15×15 (hard); the size button cycles them.

Objective:

Reveal the hidden picture. Every row and every column has a clue: its numbers are the lengths of the filled runs in that line, in order, with at least one empty cell between one run and the next. Fill exactly the cells the clues describe and the picture appears. Nothing is hidden behind a timer, a score or a paid hint — the whole game is the deduction.

Controls:

Tap or click (mouse, touch or pen, all handled as one pointer press): a cell to paint it with the current tool, and drag across cells to paint the same value along the row or column you are crossing. Buttons: Fill and Mark pick the tool, Undo removes the last stroke, Hint reveals one forced cell and counts up, Check counts disagreeing cells, the size button cycles 5×5 / 10×10 / 15×15, Restart clears the board, the arrows move through the 36 puzzles and Rules opens the explainer. Keyboard: F fill, M (or X) mark, U (or Ctrl/Cmd-Z) undo, H hint, C check, R restart, T cycle size, arrow keys change puzzle. Every button is at least 30px tall and on a phone at least 34px; a 15×15 cell is about 21px on a 390px-wide screen. Add ?puzzle= to the URL to start on a puzzle number or a tier, for example ?puzzle=hard or ?puzzle=25.