Convert JFIF to PNG without ending up with a 17 MB file
Converting a JFIF to PNG does not undo anything. The JPEG compression already baked into those pixels stays exactly where it is, and no converter can reverse it. What changes is everything that happens afterwards: PNG is lossless, so every future crop, edit, and re-save keeps the pixels it was given, and PNG has a real alpha channel that JPEG structurally cannot hold.
The part most converter pages leave out is the size. A full colour PNG of a photograph is enormous. Our 4.82 MB test photo came back at 16.86 MB, roughly three and a half times bigger, and pixel for pixel identical to the JFIF it came from. That is not a fault in the conversion. It is what lossless means on an image with millions of slightly different colours.
What you actually gain
Two things, and they are worth being precise about. The first is that quality stops degrading: a JPEG that is opened, edited, and saved five times loses a little each round, while a PNG does not. The second is transparency. A JFIF has none to carry across, so your PNG starts fully opaque, but the format can now hold an alpha channel once you add one in an editor.
A portrait photo stays a portrait photo
Phones do not rotate pixels. They record how the camera was held in an EXIF orientation tag and leave the image as the sensor saw it. Applying that tag is only half the job: if the converter turns the pixels but leaves the tag behind, the viewer applies it again and the photo lands sideways in Chrome, on an iPhone, and in Windows Photos.
We rotate the pixels and clear the tag. A test file tagged with orientation 6 came out of the PNG converter at 800 by 1200, upright, with no orientation tag left in it, and a note on the result saying so.
Keeping the file from ballooning
Palette compression is available as a checkbox. It reduces the image to a limited set of colours, which makes a photographic PNG dramatically smaller at a small cost in colour accuracy. On a photograph the difference is hard to see; on a gradient or a sunset it can show as faint banding, so it is off unless you switch it on.
The compression effort setting is separate and does not touch the pixels at all. It only decides how hard the encoder works to pack the same data, trading processing time for file size. Because nothing is thrown away, the result is labelled Lossless rather than given a quality number.
When PNG is the wrong choice here
If the plan is to share the photo, upload it, or store it as it is, PNG gives you a much larger file for no visible benefit. Keep it as JPG in that case. PNG earns its size when the file is going back into an editor, when a tool on the other end only accepts PNG, or when the image is not really a photograph: a screenshot, a logo, a diagram, or anything with flat colour and sharp edges compresses well as PNG.
Colour, and what happens to your file
The embedded colour profile is kept by default, or converted cleanly to sRGB if you choose that instead. Dimensions come back exactly as they went in. Convert one file or a whole batch, and a batch is returned as one ZIP with the original file names. No account, no watermark, and finished files are deleted an hour later.
What you get
- A lossless PNG, pixel identical to the JFIF you uploaded, verified at a maximum per pixel error of 0
- EXIF orientation applied to the pixels and the tag then cleared, so the photo is not turned twice
- Optional palette compression when a full colour PNG is larger than you need
- A format that can hold transparency, ready for the alpha channel you add later
- Original dimensions and the embedded colour profile, both preserved
- Free, no account, no watermark, and files deleted after one hour
What's next?
If you only wanted a normal .jpg extension and a smaller file, JFIF to JPG is the shorter route. To keep the JFIF format and cut the size instead, use Compress JFIF. To collect several images into one document, try JFIF to PDF.