# Are rotation matrices tensors?

Are rotation matrices tensors? If no, why? I'm not sure about it, for example considering the $$z$$-axis rotation matrix when I rotate the coordinate system the rotation matrix around the old $$z$$-axis change form.

• Matrices are never tensors. Some tensors can be represented by matrices. Tensors are multilinear maps and not matrices – Dani Oct 13 at 16:45