Convert JPG to PNG

JPG (also written JPEG) is the standard format for photographs. It shrinks pictures by discarding detail the human eye is unlikely to notice, which is why a photo straight from a camera or phone is a manageable size rather than enormous.

That compression is lossy and it is cumulative: every time a JPG is opened, edited and saved again, a little more detail disappears for good. Text and sharp edges suffer first, picking up faint smudges known as artefacts.

The main reason is to stop the decay. Converting to PNG will not restore detail that a JPG has already lost, but it does freeze the image where it is — every later save keeps exactly the pixels you have now, which matters if a file will be edited repeatedly.

The other reason is transparency. Only PNG among the two supports a transparent background, so if you plan to cut out a logo or a product and place it over another design, you need the file in PNG first.

Choose PNG when the image contains text, screenshots, line art or anything with hard edges, and when you need transparency or plan to keep editing the file. It stays perfectly sharp.

Stay with JPG for ordinary photographs you simply want to share or store. PNG files of photos are far larger with almost no visible benefit, so converting a holiday snapshot mainly costs you disk space.