Compare JPG/PNG/GIF images

Compare the file sizes and also image quality, for
  1. photographs (JPG is the winner)
  2. diagrams (PNG is the winner)

1. Photographs

file photo.jpg

(saved at "quality=10%")

size: 11616 bytes

file photo2.jpg

(saved at "quality=50%")

size: 37955 bytes

file photo.png

size: 90783 bytes

file photo.gif

size: 105065 bytes

2. Diagram

file diagram.png

size: 1071 bytes

file diagram.jpg

size: 7173 bytes

file diagram.gif

size: 1400 bytes