Will rotating an image reduce its quality?
For 90, 180 and 270 degree rotations of PNG, WebP or GIF images, there is no quality loss since the pixels are simply rearranged without re-encoding. For JPEG output, the image is re-encoded at 92% quality, which is imperceptibly different from the original. For arbitrary angle rotations like 15 or 45 degrees, there is a small amount of softening at pixel edges due to the interpolation required to rotate a rectangular grid by a non-right angle. This is true of all image rotation tools.