The core difference
JPG uses lossy compression: it discards detail the human eye barely notices to make files much smaller. PNG is lossless: every pixel is preserved, so files are larger but quality does not degrade.
| Criterion | JPG | PNG |
|---|---|---|
| Photographs | Very suitable | Files get very large |
| Logos / drawings / text | Edges can blur | Very suitable |
| Transparent background | No | Yes |
| Re-saving | Quality drops each time | Quality preserved |
Quick decision guide
- Product or landscape photo → JPG (or WebP/AVIF).
- Logo, icon, screenshot, transparent image → PNG (or WebP).
- A file you will keep editing → PNG; the final published version → JPG/WebP.
Use PNG to JPG and JPG to PNG to convert. Converting JPG to PNG does not bring back lost detail; it only prevents further lossy saves.