Fold the Shape is a paper folding puzzle played forwards. You start with a flat 4 × 4 square and a target outline beside it on the mat. Each fold flips everything on one side of a crease over to the other side, and the round ends when the paper and the outline are exactly the same shape in exactly the same place.
How to play
Choose a crease direction: vertical, horizontal, or one of the two diagonals. Then tap the mat near where you want the crease, or step it along with the arrow buttons. The two fold buttons fold one side or the other over. Hold a pointer over a fold button, or focus it with the keyboard, to preview the flap and where it will land before you commit.
Creases run along the mat’s grid lines and its 45-degree diagonals, and only creases that cross the paper are offered. A fold that would push paper off the mat is disabled. Undo steps back one fold and Start over unfolds the paper flat, but neither takes a fold off your count.
A worked example
This Easy outline needs exactly two folds. The yellow dashes mark the outline, the red dashes mark the next crease, and the shaded part of the paper is the flap about to fold over it.
- First fold. The lower-left part folds over the dashed falling diagonal crease.
- Second fold. The upper-left part folds over the dashed rising diagonal crease. The paper now matches the outline.
Two rules that make it easier
A fold keeps at least half the paper
Folding never adds area, and it can never remove more than half: the part that stays put and the flap that moves are both still there afterwards, and the larger of the two is at least half the paper. So a 16-square sheet needs at least one fold to reach 8 squares, two to reach 4 and three to go below that. Compare the outline’s size with the paper’s before you start, and you know roughly how many folds you will need.
The last crease runs along the outline’s edge
After the final fold, everything sits on one side of that crease, and the folded flap lies right against it. So the last crease is always one of the outline’s own straight edges. Look for an edge of the outline that the paper could fold back onto, then ask what shape the paper must be one fold earlier. Working backwards like this is usually quicker than trying folds at random.
Pick an edge of the outline as the last crease. Mirror the outline across it: the paper before that fold has to fit inside the outline plus its mirror image.
What changes between levels
| Level | Shapes | Fewest folds | Time each | Smallest outline |
|---|---|---|---|---|
| Easy | 3 | 2 | 1 minute | 5 squares |
| Standard | 3 | 3 | 1½ minutes | 4 squares |
| Hard | 2 | 4 | 2½ minutes | 3 squares |
The fewest-folds figure is exact at every level: each outline needs that many folds and cannot be made in fewer.
How your score works
Matching the outline is worth 72% of the score. Fold efficiency is worth 23%: the fewest possible folds divided by the folds you made, so matching a three-fold shape in six folds earns half of that share. Pace is worth 5%, measured against 20, 35 and 60 seconds a shape on Easy, Standard and Hard, and only counts for shapes you matched. An unmatched shape scores nothing. Easy, Standard and Hard apply 0.96, 1.00 and 1.04 adjustments.
Undos and restarts are recorded with your result so you can see how you worked, but they are not a separate penalty; the folds they cost are already in your count. Scores compare your own attempts only.
How every outline is made and checked
The paper is modelled exactly. Every square of the mat is cut along both diagonals into four triangles, and every allowed crease runs along triangle edges, so a fold maps whole triangles onto whole triangles with no rounding. An outline is made by folding the square at random the stated number of times, never revisiting an earlier shape and never going below the level’s smallest size.
A breadth-first search then tries every possible sequence of fewer folds. It skips shapes that are already too small, or too large to shrink to the outline in the folds left, and it only tries the outline’s own edges as the last crease, for the reasons above. Our tests check that these shortcuts never miss a route by comparing them with a plain search that checks every fold. If any shorter route exists, the outline is thrown away. Standalone attempts use a fresh seed, so reloading gives new outlines.
Keyboard, touch and screen readers
Every control is a real button at least 44 CSS pixels in size. Press 1 to 4 to pick a crease direction, the arrow keys to move the crease, and Z to undo; Tab reaches the fold buttons. The clock stops if you pause or hide the page, and the mat is covered until you choose Resume.
Screen readers hear the chosen crease described in words, each fold as it happens, and how many squares the paper and the outline cover. Matching an outline still depends on seeing its shape, so this is a visual game, and the Accessibility page says so.
Fold the Shape questions
Does it matter which way I reach the outline?
No. Any sequence of folds that leaves the paper covering exactly the outline counts as a match. The fewest-folds figure is only there so you can see how close to the shortest route you came.
Do undone folds count?
Yes. Every fold you make is counted, even if you undo it or start over afterwards. Undo is there so you can explore, but the score rewards folds you meant.
Why can some folds not be made?
The paper has to stay on the mat. When folding a large part across a crease near the edge would push it off, that fold button says so and stays disabled.
Is the fewest-folds number guaranteed?
Yes. Before a shape is shown, a search tries every possible sequence of fewer folds and confirms that none of them produces the outline.
Is Fold the Shape in the Daily Brain Workout?
No. How long a shape takes depends on when you spot the route, so it can run much longer than a short Daily station. It is a standalone game with its own records.