Here is a PlyViewer demo: PlyViewer
Just Drag&Drop your ply file into the black area and wait until it’s loaded.
For now, only PLY files with float xyz and uchar rgb and up to ~8m points are supported. For example:
element vertex 462312 property float x property float y property float z property uchar red property uchar green property uchar blue
If you don’t have a supported ply file, try this one: vienna_parliament_relief.ply