Quick answer
When to convert PNG to JPG
// Answer
Convert when the image is a photograph and the file is too big — an upload form rejecting it, an email bouncing, a page loading slowly. Think twice about screenshots, logos and diagrams: JPG blurs sharp edges, and transparency cannot survive it — see-through areas are filled with white.
The trade
What you gain and what you give up
| PNG | JPG | |
|---|---|---|
| Size of a photo | Large | Roughly a fifth |
| Detail | Every pixel exact | A very close approximation |
| Transparency | Yes | No, filled with white |
| Sharp text and lines | Clean | Fuzzy at the edges |
| Re-saving repeatedly | Safe | Degrades each time |
The quality slider above controls how much JPG is allowed to approximate. 85 is a good default. Lower settings show blocky patches sooner, first in flat areas like skies.
FAQ
Frequently asked questions
Yes, a little. PNG is lossless and JPG is not, so the JPG throws away detail to get small. At quality 85 that is usually hard to see on a photograph at normal viewing size. On a screenshot with sharp text or flat colour, it shows as fuzz around the edges — keep those as PNG.
Because JPG is allowed to approximate. A photograph saved as PNG stores every pixel exactly; as JPG it stores a very close guess. For photographs the guess is worth it, often at a fifth of the size.
JPG cannot store transparency. This converter fills any see-through area with white, so you get a usable picture rather than a black background. If you need to keep the transparency, convert to WebP instead — the option is on the tool above.
No. Your browser decodes and re-encodes the image on your own machine. There is no server in the path, and the page keeps working with your Wi-Fi switched off.