How to Check the DPI of a JPGby William Garmany
Checking the dots per inch of a JPEG or JPG image in Microsoft Windows takes just a few seconds. The main advantage to having more DPI is the ability to enlarge the image. Low DPI images will look grainy when enlarged or will print a smaller image. With more DPI, you can enlarge or shrink the image and it will still look great. An image with a higher DPI is also more likely to display clearly on your screen.
Navigate to the JPG image on your computer that you want to check the DPI on.
Right-click the file and click "Properties" from the list.
Click the "Summary" tab and view the horizontal and vertical DPI of the of image.