To provide prospective buyers with the best possible quality photos, you’ll want to select an appropriate file size for online use. Open your photo in an image editing program and follow these steps:
Look for a command called “Image Size” or “Resize” to enter exact pixels.
Select the option to keep aspect ratio so the image is resized proportionately.
Enter a width between 565 and 640 pixels.
Select Save As from the File menu.
Select JPEG (.jpg/.jpeg) or GIF (.gif) as the file format and save the image to your hard drive.
When choosing the compression level, keep quality in the medium to high range. Also, keep the file size under 100 KB with a resolution of 72dpi.