02/09/2015
A side-by-side comparison of Facebook's PNG and JPEG formats. Facebook only supports PNG up to 1024kb, so to achieve that size, the resolution was cut from 2048x1365 to 1086x724. The JPEG file was uploaded on maximum quality settings at 2048x1365 with a file size of 1.712MB, and will be compressed by Facebook to 41% of that quality and will result in a 200KB file.
My experiment is simple:
Download both, and view them side-by-side, first with the JPEG zoomed out to match the display size of the PNG, and the second time with the PNG zoomed in to match the display size of the JPEG.
You'll make two important findings.
1. Though the JPEG has a higher resolution, when viewing it at the PNG's native resolution at 53%, it is of noticeably lower quality, especially in the areas where the strings around the planet are.
2. Though the PNG has a lower resolution, when viewing at the JPEG's native resolution at 187%, the PNG holds its own very nicely, and the only major difference in quality is a minor loss in detail in the planet and the strings around it. One area in which the PNG is noticeably better is the dark areas in the top left corner, where there are virtually no artifacts compared to the JPEG.
You may draw your own conclusions, but for me, the choice is simple. I'm going with PNG, because even at the cost of 50% of the resolution, the laughably bad quality of the JPEG means all those extra pixels aren't really doing much.
