This will not improve your photo
Converting JPG to PNG cannot recover quality. JPEG threw detail away when the file was first saved, and that detail is gone. PNG will store what remains exactly — artefacts included — in a file several times larger. It is a faithful copy, not a repair.
"Convert to lossless PNG" can read like an upgrade. It is a different set of trade-offs, and there are three situations where those trade-offs are the ones you want.
When you genuinely should convert
| Situation | Why PNG is right |
|---|---|
| Something demands PNG | A form, a design tool, a game engine, an app icon pipeline. No argument to have — it wants PNG. |
| You are about to edit it repeatedly | Every re-save of a JPG degrades it again. Convert once to PNG, do your editing, and export to JPG at the end. That is one round of loss instead of five. |
| You need transparency | JPG cannot hold a transparent area at all. PNG can. Convert first, then cut the background out in an editor. |
Outside those three, you are usually better off leaving the file as a JPG. If it is simply too large, compress it or resize it — going to PNG will make it bigger, not smaller.
Going back
If you arrived here from a PNG that was too big, you want PNG to JPG instead — that is the direction that saves space. For the web specifically, PNG to WebP and JPG to WebP usually beat both, and the format benchmark will measure all three on your own files rather than quoting an average from someone else's photographs.