Convert JPG to PNG

What a PNG will not do

Three expectations come up again and again, and converting meets none of them:

• It will not make the background transparent. A JPG has no see-through pixels, so its white or colored background is just more pixels, and the PNG keeps them. Taking a background away is a separate job: remove the background first, then export the PNG.
• It will not bring back lost detail. The blockiness or smudging a JPG picked up when it was compressed is part of the picture now, and the PNG preserves it faithfully.
• It will not make the file smaller. PNG is lossless, so a photo grows, often a lot.

What a PNG does promise is that nothing more is lost from here on, however many times you open it, change it and save it again.

When PNG is worth it

There are good reasons to want a PNG copy of a JPG:

• Edits in several rounds. Every time a JPG is saved, it is compressed again and loses a little more. Work on a PNG and save the final JPG once, at the end.
• Text, arrows and boxes on top. Captions and shapes you add with the Photo Editor's Text and Shapes tools stay crisp in a PNG, where a JPG would soften their edges. See adding text to a picture.
• Forms, templates and tools that ask for PNG. Some design tools, templates and upload forms accept nothing else.
• A clean master copy before you hand a picture to someone who will edit it further.

If none of these apply and the JPG opens where you need it, there is nothing to gain from converting. If one does, the PNG costs you disk space and nothing else. For your own edits across several sessions, File › Save does the same job better: it keeps the work as an Octoolo project, every layer intact.

Why the PNG is so much bigger

JPG saves space by describing the picture in small blocks and dropping the fine variations your eye is least likely to miss. PNG cannot drop anything; it can only pack the exact pixels as tightly as possible. That works brilliantly on flat colors and poorly on photos, where almost every pixel differs from its neighbors.

So a phone photo that was a few megabytes as JPG can become a PNG several times that size. If that is a problem, pick a smaller width under Size in Export, from 3840 down to 512 pixels: fewer pixels make a smaller PNG. If size matters most and you do not need PNG, keep the JPG, or make a WebP of it.

Export shows the PNG's estimated size before you commit.

Phone photos: rotation and hidden notes

Phone cameras often store a photo sideways and add a small note telling programs to turn it. Programs that ignore the note show the photo lying on its side, which is a common surprise after converting. Octoolo applies the turn to the pixels as it opens the JPG, so the PNG is upright everywhere, with no note needed.

The same photo usually carries other notes too: the GPS position, the phone model, the date and time. None of them are written into the PNG. That is handy when the picture is going online, and worth knowing if you sort your photos by those details: keep the original JPG for your library.

While you edit, Ctrl Z steps back one change at a time, and the History panel beside Layers jumps back to any earlier step.