hJPEG is a freeware portable app to help image file size reduction by viewing the effects of changing the compression and dimensions of a JPEG image, before saving or copying.

hJPEG can accept most common image formats which it will convert to JPEG format if necessary.

Most standard images can be compressed further without obvious detrimental effect, giving significant saving in file size. However, it does depend on the compression quality of the original image and the size of the image. For example, if the original is compression quality is 70 then saving it again at 70 means it is 70% of 70. The viewed size of the image also has a part to play, the artifacts and quality will become more evident as the image is expanded. The advantage of hJPEG Is that quality can be visually assessed not guessed.

Files can be dropped on either a desktop shortcut or the open application. Only one file is accepted.

The image is normally shown proportionally fitted to the window. Double-clicking on the image will show it full size. NOTE that when showing full size, the window dimensions are shown in the caption bar in brackets.

Images can also be pasted from the clipboard.

After dropping an image file or pasting from the clipboard, it will show in the window with ORIGINAL file size and image dimensions in pixels. This is after conversion to JPEG at default compression if necessary.