Compress JPEG file online
Select a picture on your computer or phone, set desired JPEG quality from 1 to 100 (compression level) and then click OK button at the bottom of this page. All other settings are already installed by default. If necessary, the quality (compression) level of any jpg image can be determined here.
Main parameter that reduces file size is "quality" of JPEG (or compression level). Lower quality (60-70) gives smaller file size. Subsampling in settings allows to optimize image details to further reduce the file size in kilobytes. Subsampling 1x1 is more suitable for small pictures. Subsampling 2x1 is most common and used in almost all digital cameras, this parameter is good for large images more than 1 megapixel or >1366x768. Subsampling 2x2 gives smallest file size, but the image quality may be low, this option is suited for very blurred pictures.
The original image is not changed. You will be given other processed image in JPG format.
On the photos of the "Red pepper after the rain" is shown level of JPEG quality for comparison:
Sizes of this jpg image, depending on the level of quality (Q - quality, KB - size in kilobytes):
Q 10 = 2 KB; Q 15 = 2,7 KB; Q 30 = 4,3 KB; Q 50 = 5,9 KB; Q 60 = 6,7 KB; Q 70 = 7,9 KB; Q 80 = 9,8 KB; Q 90 = 14,1 KB; Q 100 = 46,5 KB.
Also you can compress JPG specifying the desired file size in KB or reduce size of picture in pixels.