- JPEG:
- Good:
- Photographs
- Game screenshots
- Movie stills
- Desktop backgrounds
- Bad:
- Windows application screenshots
- Line art and text
- Comic strips
- Anywhere where fine lines or sharp color contrast is needed
- Good:
- PNG:
- Good:
- Text, line art, comic-style drawings, general web graphics
- Windows application screenshots
- When accurate reproduction (lossless) is required (24 bit PNG)
- When alpha channel support is required
- As a general replacement for anything that is a non-animated GIF
- Bad:
- Photos, in-game screenshots (only when quality is not important and you're looking for small files)
- Disappointing browser support for 32 bit PNGs from Microsoft and others
- Good:
- GIF:
- Good:
- Where animations are required
- Widespread browser support
- Bad:
- Large file sizes compared to PNG for the same quality
- Often limited to 256 colors (8 bit)
Thank you, random website.