Lights Out - Free Online | FunToolX
Use Lights Out online for free, no download required. FunToolX offers hundreds of fun online tools.
About this tool
Lights Out is a free online game. Toggle crosses to switch every light off. Play instantly — no install, no waiting. It runs entirely in your browser — no download or sign-up needed.
Some lights in the N×N grid are on and off. Clicking on a grid will switch the states of itself and the four adjacent grids (bright becomes extinguished, extinguished becomes brighter). The goal is to find a click order to turn off all the lights.
This game has mathematical rules: each grid only needs to be clicked once at most (clicking twice equals no dots), and the click order does not affect the final result. The optimal solution can be solved using linear algebra (exclusive-OR equations).
The difficulty ranges from 3×3 to 5×5, and the greater the number of initial lights, the more difficult it becomes. The page uses CSS Grid to draw a grid, and after clicking, use CSS transition to switch the visual effects of the light and off states. Provide a prompt function to show where to go next.
In the light-off game, click on a grid in the N×N grid to switch between itself and adjacent grids. The goal is to turn off all lights.