When converting PNG to JPG makes sense
When to convert PNG to JPG| Your PNG is… | Convert to JPG? |
|---|
| A photo (camera image, scanned picture) | Yes. Typically several times smaller at quality 80. |
| A form or portal requirement says “JPG only” | Yes. Combine with a KB target if there is a size limit. |
| A screenshot with text, a logo or a diagram | Usually not. JPG blurs sharp edges; try Compress PNG instead. |
| An image with a transparent background | Only if you don’t need transparency; otherwise use PNG to WebP. |
Transparent areas
JPG has no transparency. Kilomill blends transparent and semi-transparent pixels onto a solid colour: white by default, or any colour under Advanced → Background for transparent areas. Pick the colour of the page or document the image will sit on, and soft edges will blend in naturally.
Questions and answers
Will PNG to JPG lose quality?
JPG is lossy, so a tiny amount of detail is discarded. At quality 80–90 photos look the same; sharp text and lines may show faint halos, which is why screenshots are better kept as PNG.
Why is my JPG bigger than the PNG?
That happens with simple graphics with few colours, which PNG stores very efficiently. Keep those as PNG.
Can I convert many PNGs at once?
Yes. Add them all, then use Download all (ZIP).
Are my images uploaded to a server?
No. The images are read and compressed by code running in this browser tab, and the results are created in your device’s memory. The images are never sent anywhere, which you can confirm in your browser’s developer tools (Network tab): no request carries them. The only statistics are Cloudflare’s page-visit counts; see Privacy.