Why people convert JPG to PNG
Every time a JPG is edited and saved again, it is compressed again and loses a little more quality. A PNG copy can be edited and saved over and over without further loss, which makes it a safer working file once you have decided to keep editing.
- Some programs, templates and upload forms only accept PNG.
- Screenshots, scans and graphics saved as JPG are often easier to work with as PNG, because PNG keeps sharp edges exactly.
- You plan to add transparency later in an image editor. JPG cannot hold it, PNG can.
What a PNG can and cannot fix
Converting does not improve the picture. The blocky patches and blur that JPG compression created are still there, they are just stored exactly now. If a photo looks rough as a JPG, it will look the same as a PNG.
The price is size. A JPG gets small by discarding detail, while PNG keeps every pixel, so a PNG made from a photo is usually several times bigger. If your goal is a smaller file, go the other way with PNG to JPG, or try JPG to WebP for websites.
Settings that matter for this conversion
- Make PNG files smaller runs a lossless optimiser that tries different ways of packing the same pixels. It often saves a lot on graphics and some on photos, but it is slower and is skipped automatically for images above 16 megapixels.
- Metadata: PNG can store an EXIF block, but not every program reads it. With Keep, the camera details, date and GPS location from the JPG are copied over, and the rotation tag is reset because the picture is already turned the right way up.
- Colours are converted to sRGB and no colour profile is embedded. A wide-gamut photo can look slightly less vivid.