Convert JPG to PNG

JPG to PNGの使い方

1. 1

   Add JPG or JPEG files

   Drop up to 10 photos or scans of up to 25 MB each; .jpg, .jpeg and .jfif all work.

2. 2

   Keep PNG selected

   PNG has no quality setting: every pixel of the decoded JPG is stored as it is.

3. 3

   Wait a moment

   Each image is written and optimised with OxiPNG; large photos take a few seconds each.

4. 4

   Download

   Save the PNGs individually, or the whole set as converted-png.zip.

JPG to PNG について

Converting a JPG to PNG wraps the picture in a lossless format. The pixels you see in the JPG are decoded once and stored exactly, so from this point on the image can be opened, edited and saved again as often as you like without losing any more quality. That is the main reason to do it: JPG degrades a little every time it is re-saved, while PNG never does, which matters when a picture goes through several rounds of editing, annotation or design work.

There are other reasons too. Some apps, slide templates and upload forms accept PNG only; graphics tools that add transparency, such as a background remover, need a format that can store it; and screenshots that were saved as JPG by mistake are easier to annotate as PNG. Photos are turned upright using their orientation tag, colours are converted to sRGB, and EXIF data such as the camera model and GPS location is left out.

Two expectations to correct before you convert. The PNG will be larger, often three to eight times for a photo, because lossless compression can't discard detail the way JPG does. And it will not look better: blockiness, blur and colour banding that JPG compression already introduced are preserved faithfully, because the conversion can only keep what is there. The background stays as it is, too; a PNG can hold transparency, but converting doesn't create it. To cut out the subject and make the background see-through, use the background remover.

主な機能

JPG to PNG：よくある質問