PNG vs JPG: choose the right image format
Choose a format for the next use of your image: a photo upload, a transparent logo or a screenshot with small text. Changing the filename extension is not a conversion.
Start with the image content
JPG uses lossy compression and is suited to photographs. PNG uses lossless compression and supports transparency, making it useful for logos, diagrams and sharp text. JPG does not retain transparent pixels.
Reference: MDN: image formats
What happens to a transparent PNG?
In PNG to JPG, transparent areas are filled with the selected background: white, black or a custom color. Check the edges of a logo against that color before downloading. If you still need transparency, keep PNG or use a format that supports it.
- Choose the original PNG in PNG to JPG.
- Choose a background and JPG quality. Leave resizing off to keep the pixel dimensions.
- Convert, inspect the preview and compare the actual output size.
Converting back cannot restore detail
JPG to PNG creates a PNG from the pixels the browser decodes. It cannot reconstruct detail already lost in a previous JPG save. A larger PNG is therefore not evidence that the picture improved. Keep the original file when trying several export settings.