Online – web and blogging

Online display is typically set to 72dpi, which is a standard resolution for viewing images online. Since this is a fixed resolution, the more pixels there are in the file, the larger, physically, it will be displayed. However, most websites (and blogs) have a finite size for displaying images, which is impacted by the design intent, the speed of the internet connection, and storage space, but ultimately by the company offering the service. I use Google Blogger, which is free. It offers several image display sizes, topping out at only 640 pixels wide for the largest image view.

So, if the resolution (number of pixels) in your file exceeds the number that's needed to display an image at a fixed size and resolution, it's essentially pixels wasted and might slow the display onscreen significantly (and potentially switch your audience off). If you use a commercial site such as Google Blogger, the file size is automatically restricted in the upload process...