Convert JPG to PNG when an app needs lossless files, or when you plan to edit and re-save without more compression loss.
PNG ignores the quality setting because it is lossless. Enhance uses smooth upscaling and sharpening, not AI, so it makes soft images crisper but can't recover detail that isn't there. If your browser can't write AVIF, that option reports an error and you can pick another format.
Converting does not restore detail already lost in the JPG, and the PNG will usually be larger.
No. It stops further loss from repeated saves, but it can’t bring back detail already removed.
PNG stores every pixel without lossy compression, so photos become large.