Maximum Texture Size in Blender?

I have made a texture in photoshop with a size of 4k by 4k and I saved it as a png. When I import it into blender it gets blocky. Is there a maximum texture size for blender?

Do you mean pixelated in the final rendered image or in the viewport?
I’ve used images with more than 4000 x 4000 px and they render well.

This would be an effect of even at 4k x 4k your image is being stretched to fit. You can either make your texture even still larger, or scale your object down so that the texture isn’t streched.