See the pattern.
Find the spark.

Your goal is simple: turn every light on. The interesting part is how one small move changes its neighbors.

One tap, a cross of changes

Tap a tile and it flips from dark to light, or light to dark. Its directly adjacent neighbors above, below, left, and right flip too. Diagonal tiles stay as they are. A corner tap changes three lights; an edge tap changes four; a middle tap changes five.

Use a mouse or touch screen. On a keyboard, Tab reaches the board, arrow keys move between tiles, and Enter or Space activates the focused tile.

Two useful observations

A repeated tap cancels itself. Tap any tile twice and everything returns to its previous state. You only need to consider whether a tile is tapped an odd or even number of times.

Order does not change the result. A set of taps produces the same final board in any order. This makes it easier to think about a pattern of tiles to tap, rather than memorize a long sequence.

Try chasing the lights

For a systematic approach, first choose which tiles to tap in the top row. Then work downward: whenever a tile in the first row is dark, tap the tile directly beneath it. This makes the first row fully lit. Apply the same rule to the second and third rows.

The bottom row may still be wrong. That means you need a different starting choice in the top row. There are only sixteen possible top-row tap patterns on a four-column board. At least one produces a solution for every Switchlark board. This strategy finds a solution, though it may use more moves than the shortest one.

Explore without pressure

Undo reverses your most recent tap during the current session. Restart returns the current puzzle to its original board. A little hint outlines one tile from a shortest solution to your current board; the result records how many hints you requested. Hints are never paywalled.

The daily puzzle changes at midnight UTC. Everyone receives the same daily board, so you can compare results. Practice starts at board one and lets you continue through numbered boards after each solution. Your best scores and unfinished puzzles stay in this browser.