PNG and JPG solve different problems. PNG is lossless and supports transparency. JPG is lossy but produces much smaller files for photographs.
Keep it as PNG when...
Your image is a logo, icon, screenshot, or anything with sharp text or transparent background. JPG smears sharp edges and can't handle transparency.
Convert to JPG when...
Your image is a photograph and file size matters (email, upload forms, website). JPG can be 5–10× smaller with no visible quality loss on screen.
FAQ
Do I lose transparency?
Yes. JPG doesn't support transparency — transparent areas become white during conversion.
Will screenshots look bad?
Screenshots with text or UI edges look worse as JPG. Keep those as PNG.