About converting JPG to PNG
JPG uses lossy compression: every save discards a little detail to keep the file small, and the loss accumulates each time the image is re-encoded. PNG is lossless, so converting to it freezes the image exactly as it is now. That makes PNG the right target when you are about to edit an image repeatedly, or when you need a clean master to export other sizes from.
The other reason to convert is transparency. JPG has no alpha channel and fills any transparent area with solid white, which is why a logo saved as JPG shows a white box behind it. PNG keeps the alpha channel, so once converted you can erase the background and the transparency will survive.
What converting cannot do is restore detail that JPG compression already threw away. If the original has visible blocking or halos around hard edges, those artefacts are part of the image and will be preserved faithfully in the PNG. Convert from the highest-quality JPG you have rather than from a copy that has been saved several times.
Frequently asked questions
- Does converting JPG to PNG improve image quality?
- No. Converting to PNG stops any further loss, but it cannot restore detail that JPG compression has already discarded. The PNG will look identical to the JPG you started from - the benefit is that editing and re-saving it from then on costs nothing in quality.
- Will the PNG file be larger than the JPG?
- Usually yes, often several times larger. PNG is lossless, so it cannot reach the file sizes JPG achieves by discarding detail. PNG compresses flat colour and sharp edges well, so logos and screenshots stay reasonable, while photographs grow the most.
- Can I get a transparent background by converting to PNG?
- Converting gives the file an alpha channel, but it does not remove the background for you. A JPG has already flattened any transparency to solid colour, so you convert to PNG first and then erase the background in an editor - the transparency will be preserved from that point on.