JFIF to PNG

Why convert JFIF to PNG?

JFIF is simply a JPEG with an unusual file extension, most often produced when saving an image from certain browsers. Some software refuses it purely because of the extension.

PNG is lossless and supports transparency, which makes it right for logos, screenshots, diagrams and anything with sharp edges or text. It is the wrong choice for photographs, where it produces files several times larger than necessary.

What changes, and what does not

The conversion is effectively a rename with a clean re-encode, so quality is unchanged.

Converting a photographic PNG to JPEG typically cuts the size by 80% or more with no visible difference, which is why upload forms so often ask for it.

It happens on your device

This conversion runs in your browser. The image is decoded, drawn to a canvas and re-encoded as PNG locally, so it is instant and the file is never uploaded. There is no queue, no daily limit and no watermark, because there is no server doing the work and therefore no cost to ration.

Converting a batch

Drop in up to thirty images at once and you get a zip back with every one converted. This is the usual case for a folder of JFIF files off a phone or camera, where converting them one at a time is the actual chore.

Quality

The quality setting controls how hard the encoder compresses. PNG is lossless, so quality affects how much effort goes into shrinking the file rather than how it looks — the pixels are identical either way.