How to play Fill the Glass
Fill the Glass is a free water physics puzzle where you draw the plumbing. A tap hangs at the top of the screen and an empty, rather sad-looking glass waits somewhere below it. The water will not go where you want on its own: the glass is off to one side, hidden behind a wall, perched on a tower or even sliding back and forth. You draw the lines that carry the water there. Each line you draw stays frozen exactly where you put it, so you can build slides, gutters, funnels and shields before a single drop has fallen.
- Look at where the tap is and where the glass is. Imagine the path a stream of water would take.
- Draw one or more lines with your mouse or finger. Watch the ink bar: when it is empty, you cannot draw more.
- Made a mistake? Tap ↶ to undo the last line and get the ink back.
- Press Pour! The tap opens and about a hundred drops of water flow out.
- Fill the glass up to the red dotted line. The percentage above the glass shows how close you are. Reach 100% and the glass smiles.
Tips for a perfect pour
- Slides need a slope. Water flows downhill and speeds up as it goes. A gentle slope keeps the stream under control; a very steep one shoots water past the glass.
- End your slide right above the glass. Water leaves the end of a line moving sideways, so finish your line just over the middle of the glass, not at its edge.
- Build a funnel for moving glasses. When the glass slides from side to side, two short lines in a V shape just above it catch the stream and drop it straight down, wherever the glass happens to be.
- Use walls as a backstop. A line that ends against a wall stops water from flying off, and a zig-zag of two lines can lower the stream step by step down a tall level.
- Shield the stream from spinners. Yellow spinners bat water away. Two vertical lines either side of the stream form a pipe that keeps the paddles out.
- Short and straight saves ink. A wobbly line costs more ink than it looks. Straight strokes earn three stars far more often, and you can always replay a level to improve your rating.
What you will find in the levels
The first levels teach the basics with a single slide from the tap to the glass. Then the puzzles grow: a tall wall that the water must jump, a shelf blocking the tap so you have to steer the stream around it, a glass standing on a tall block, and a sloping ramp that sends the water the wrong way unless you catch it. Later levels add a glass that glides from side to side, rotating paddles that knock the stream off course, a tower in the middle of the room and a final level that combines walls, a moving glass and tight ink. Each level has more than one solution, so experiment with funnels, gutters and catch-nets until you find the shortest line that works.
Why water drawing puzzles are so relaxing
Water puzzles in the style of Happy Glass became one of the best-loved kinds of drawing game because they combine two satisfying things: a clear, simple goal and a stream of water that behaves the way you expect. Watching drops tumble down your slide, splash into the glass and rise towards the line is a small reward every time. Behind the calm, these puzzles train useful skills. You predict where moving objects will land, think about angles and speed, and learn to solve problems with the fewest possible moves. Every drop in Fill the Glass is simulated as a tiny ball, so the water piles up, sloshes and spills in a slightly different way on every pour. A level you nearly solved might work with a small tweak to the angle, which makes it very hard to stop at just one more try.
More drawing puzzles to try
Like puzzles where one line changes everything? In Draw Puzzle you draw a single line to bring two balls together. For a test of a steady hand, try Draw a Perfect Circle, or let an AI guess your doodles in Quick Draw.
Fill the Glass FAQ
How do you play Fill the Glass?
Draw one or more lines with your mouse or finger to build slides and funnels, then press Pour! The tap opens and the water flows along your lines. Fill the glass up to the red dotted line to win the level.
Do my lines move when the water hits them?
No. In Fill the Glass every line you draw is fixed in place, like a solid shelf. Only the water moves, plus any spinners or moving glasses that are part of the level.
How are stars awarded?
Stars depend on how much ink you use. Fill the glass using half of the ink bar or less for three stars, up to 80% for two stars, and any full glass earns at least one star.
Can I undo a line?
Yes. Before you press Pour, tap the ↶ button to remove the last line you drew and get its ink back. The ↻ button restarts the whole level.
Does it work on phones and tablets?
Yes. Fill the Glass runs in any modern browser. Draw with your finger on a touch screen or with a mouse or trackpad on a computer. There is nothing to download or install.
Is my progress saved?
Yes. Unlocked levels and your best star rating for each level are saved in your browser on this device, so you can come back later and try for three stars.