Image formats are not interchangeable labels. They store pixels differently and support different features. Choosing the format based on the image and its destination can improve quality, compatibility and file size.
JPG: practical for photographs
JPG uses lossy compression and is widely supported. It is a strong default for photographs when transparency is not needed. Repeatedly saving and re-encoding JPG files can gradually reduce quality, so keep an original when the image matters.
PNG: useful for transparency and crisp graphics
PNG supports transparency and uses lossless compression. It is often a good fit for logos, interface screenshots, diagrams and graphics with sharp text. Photographic PNGs can become much larger than JPG or WebP files.
WebP: efficient for modern web delivery
WebP supports both lossy and lossless modes and can support transparency. It is widely used on the modern web because it can reduce transfer size. Some older software or specialized upload systems may still prefer JPG or PNG, so compatibility can be the deciding factor.
Conversion cannot restore missing detail
Turning a JPG into PNG does not reverse the compression that already happened. The new PNG stores the pixels it receives without additional lossy compression, but the original JPG detail is not recreated.
Transparency needs special attention
When a transparent PNG or WebP becomes JPG, transparent areas must be replaced with a solid background because JPG has no alpha transparency channel.