Missing Square Puzzle

The missing square puzzle is a visual illusion that involves a square with a smaller square removed from one of its corners.

The puzzle is presented in such a way that the surrounding rectangles appear to be the same size, but when the lines of the squares are measured, it becomes clear that they are not.

The missing square puzzle is used to demonstrate the importance of context in visual perception and how our brain can be easily fooled into perceiving something that is not actually true.

It also highlights the limitations of our visual system and how it can be influenced by our assumptions and expectations.


Missing Square Puzzle
Missing Square Puzzle


Table of Contents


How does the Missing Square Puzzle?

The missing square puzzle works by exploiting the way the human visual system processes and interprets visual information.

The brain relies on various cues, such as perspective, shading, and the relationships between objects, to make sense of the visual world.

In the missing square puzzle, the brain uses these cues to perceive the surrounding rectangles as being the same size, even though they are not.

The illusion works because the brain is influenced by the contextual information provided by the surrounding rectangles and their relative size, rather than relying solely on the actual measurements of the squares.

This leads to a misperception of the size of the squares and the overall shape of the puzzle, creating the illusion of a missing square.


Versions of the Missing Square Puzzle

The following is an alternative Missing Square Puzzle:



Missing Square Puzzle
Missing Square



Missing Square Puzzle
Missing Square Puzzle – Solution Shown



Illusions like the Missing Square Puzzle

The missing square puzzle is a type of size-constancy illusion.

Size-constancy illusions refer to situations where the perceived size of an object remains constant, even though its physical size changes.

In the missing square puzzle, the perceived size of the surrounding rectangles remains constant, even though their physical size changes.

The illusion is a demonstration of how our visual system processes and interprets visual information and how it can be influenced by contextual cues, such as the relative size of surrounding objects.

The missing square puzzle is also sometimes referred to as an optical illusion or perceptual illusion.

Some related illusions include the following:

Illusory contours are created by the brain’s interpretation of visual information, such as the arrangement and contrast of lines and shapes in the visual field.

Kanizsa Triangle Illusion
The Kanizsa Triangle

The Muller-Lyer illusion: an illusion in which two lines of the same length appear to be of different lengths due to the presence of arrowheads at the ends of the lines.


müller-lyer illusion



The Poggendorff illusion: an illusion in which two lines that are parallel in reality appear to be skewed or converging due to the presence of a third shape in the foreground.


Poggendorff illusion transparent gray bar



The Café Wall illusion: an illusion in which the lines that form a tiled wall appear to be skewed or distorted due to the presence of contrasting colored tiles.

Cafe Wall Illusion



The Zöllner illusion: an illusion in which parallel lines appear to be skewed or converging due to the presence of intersecting lines at an angle.

Zöllner illusion

The Ebbinghaus illusion: This illusion involves circles of different sizes, but with the same-sized circles placed close to each other. The brain perceives the smaller circles as being larger when they are placed next to larger circles.

Ebbinghaus Illusion


The T illusion: This illusion involves a T-shaped figure with a horizontal bar and a vertical bar. The brain perceives the vertical bar as being longer than the horizontal bar, even though they are the same length.


T Illusion


Moon illusion: This illusion involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.


Moon Illusion



Ponzo illusion: This illusion involves the perception of an object appearing larger or smaller depending on the size of the surrounding context.

Ponzo Illusion


All these illusions work by exploiting the way the brain processes visual information and the way it interprets the relationship between different elements in an image. Illusory contours are thought to be created by the activity of neurons that respond selectively to edges and contours in the visual field, which can be influenced by different visual cues.


Discovery of the Missing Square Puzzle

The origin of the missing square puzzle is unknown and its creator is not credited.

The puzzle has been widely used in psychology and neuroscience research to study visual perception and the underlying mechanisms of size constancy.

The puzzle has been used by researchers to investigate the importance of context in visual perception and to demonstrate the limitations of our visual system.

The missing square puzzle is one of many optical illusions that have been used to further our understanding of how the brain processes and interprets visual information.

Size constancy illusions like the Missing Square Puzzle have been studied by a number of psychologists and neuroscientists, and the discovery of these illusions is often attributed to the work of Gestalt psychologists in the early 20th century.

Gestalt psychologists, such as Max Wertheimer, Kurt Koffka, and Wolfgang Köhler, were among the first to study how the brain processes and interprets visual information, and they made significant contributions to our understanding of size constancy.

They conducted a number of experiments that demonstrated the importance of context in visual perception and how our visual system can be easily influenced by the relationships between objects.

Their work laid the foundation for the continued study of size constancy illusions and the underlying mechanisms of visual perception.

References and Resources

Check out our complete list of illusions.

Sign Up to Have Your Mind Blown