PNGs are big. For photos, JPG is 5–10× smaller at the same visual quality. Convert when you don't need transparency.
When PNG → JPG makes sense
- Photo-like PNG screenshots
- Large PNG graphics for web
- Storing many images (smaller archive)
- Email attachments
When it doesn't
- **Logos with transparency** — JPG has no alpha; your logo will get a white box
- **Screenshots with text** — JPG artifacts make text fuzzy
- **Line art / icons** — PNG is much better here
Background color
If your PNG has transparency, pick the color to fill behind it (white, black, or custom).
Quality
Default 90% is right for most photos. Bump to 95% for technical images with fine detail.