JPEG Image File Compression

Here are some samples of good and bad file compression. These images will give you an idea of the best factor to compress your images for quality and clarity. When compressing images, try to find a balance between file size and image clarity.

NEVER overwrite the original file when working with image file compression optimization, save the file under a new filename ("Save As" in the file menu).

JPEG Compression factors shown are Photoshop standard, 12 is best and 0 is worst. In older versions of Photoshop the scale went from 0-10 instead of 0-12.

Sample Compression Pictures

Size: 192k Compression Factor: 12
Image quality is perfect, however the file size is too large.

Size: 54k Compression Factor: 7
This is a good balance between file size and image quality.
The compression is for the most part unnoticeable.

Size: 22k Compression Factor: 0
The file size is good, but the quality suffers
immensely. (horizontal tearing on the child's nose, etc.)

Compression Conclusions

You can easily see from the above 3 examples that the extremely compressed images have particularly noticable compression artifacts, while the best quality image setting has the largest file size.

Greyscale conversion of highly compressed JPG images seems to make the compression artifacts even more noticable.

Maintaining a good balance between these two extremes is the best option in most cases.

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