The best replacement for png is jpg.

The best alternatives to png are rated as following:
★★★★★  jpg
★★★★★  gif
★★★★  tiff
★★★★  jpeg
★★  bmp
★  svg
★  eps
★  pdf
★  tif
★  tga
★  jpg size
  jpeg smaller
  psd
  jpeg quality
  nederland
  bitmap
  ico
  dng
  bmp quality
  jpg resolution
  manvel
  webp
  jpeg better
  brenham
  png
  .jpg

Your alternative for png is not listed? Suggest!
Speaking about png, one probably shouldn't forget about transparent background.

Other search terms related to png and their ratings are:
★★★★★ transparent background
★★★★★ transparency
★ opacity
You have in mind a companion for png and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of png in all years. Click on graph for more.
png
jpg
gif