A rectangle created with the clearRect() method is not transparent.

Question

Quizplus · Accepted Answer

The clearRect() method clears the specified rectangular area of the canvas, but it does not make it transparent. Instead, it sets the pixels within the area to the current fillStyle color, effectively erasing whatever was previously drawn in that area. To make the rectangle transparent, you need to set the globalAlpha property to a value less than 1 before drawing the rectangle.

A Rectangle Created with the ClearRect() Method Is Not Transparent