Hi I'm cleaning up my site and trying to make it run faster and I'm going through reducing the size of all of my images
something I noticed is my thumbnail images are the same file size as the original
for example one image was 50kb so I reduced the file size to 12kb in photoshop but still left it the same size and saved it as a .jpg
when I upload it through wordpress to become a thumbnail not only is it still 50kb put it is also in .png format
can anybody help me understand why?