I♥.png

PNG vs JPG

Use PNG for anything with sharp edges or transparency — logos, icons, screenshots, line art. Use JPG for photographs, where it is several times smaller at a quality difference you cannot see. The deciding question is not quality, it is whether the image has hard edges: JPG smears visibly around them, PNG never does.

PNGJPG
CompressionLossless — nothing is discardedLossy — detail is permanently removed
TransparencyYes, full alpha channelNo — forced onto a solid colour
PhotographsVery large filesSmall files, excellent quality
Text and sharp edgesPerfectly crispVisible smearing and ringing
Re-saving repeatedlyNo degradation everCompounds loss every save
AnimationNo (APNG exists, rarely used)No
SupportUniversalUniversal

Use PNG for

  • ·Logos and icons
  • ·Screenshots containing text
  • ·Line art and diagrams
  • ·Anything needing transparency
  • ·Working files you will edit again

Use JPG for

  • ·Photographs
  • ·Email attachments where size matters
  • ·Anywhere the platform rejects PNG