Matrix Multiplication Visualizer

July 11, 2026

This is an interactive web application to help visualize matrix multiplication, at least the way I visualize it! You can type in your own values to the matrices below by clicking/tapping on the cells if you want to use the default 2x2 matrix. Or, if you want a different dimensionality, you can enter your own matrix in text with the text boxes below. The syntax is "[[1,2],[3,4]]".

Note that we are being pedantic here and do not perform NumPy-style array promotion. We treat [1,2] as a $1 \times 2$ row vector which is distinct from a $2 \times 1$ column vector. To perform $\mathbf{A}\mathbf{v}$ multiplication where $\mathbf{A}$ has $n$ rows, you must enter $\mathbf{v}$ as an $n \times 1$ matrix, e.g. [[1],[2]].

Edit cells directly, or type a whole matrix into A or B. Hover (or tap) an output cell to see the row and column that produce it.