Good reasons to convert
- A form or tool only takes PNG. Some upload fields, slide templates and design tools ask for PNG specifically.
- You're going to edit it. Every time a JPG is saved, it loses a little more. A PNG can be opened, edited and saved as often as you like with no further loss, so convert once and work on the PNG.
- You'll add transparency later, for instance cutting out a logo in an editor. JPG can't hold transparent pixels; PNG can.
What it won't do
- It won't make the image better. Blur and blockiness from the JPG's compression are copied into the PNG exactly. The PNG is lossless from now on, not lossless compared with the original photo.
- It won't make it smaller. A photo as PNG is usually several times bigger than as JPG, because PNG stores every pixel exactly. If size matters, keep the JPG, or use compress to KB.
- It won't remove the background. Converting gives you a PNG that can have transparency; the pixels are all still opaque until you cut something out.
How the PNG is made
The PNG is written with the reductions a PNG optimiser makes — a palette when the image has 256 colours or fewer, grey instead of colour when there's no colour, the strongest compression level — so it's no bigger than it needs to be. The photo is turned upright and carries no EXIF data. A colour profile is kept.
The reverse, usually more useful for photos: PNG to JPG. For WebP output see JPG to WebP.