Post History

Source: https://writers.stackexchange.com/a/43512
License name: CC BY-SA 3.0
License URL: https://creativecommons.org/licenses/by-sa/3.0/

Depends on your audience.  
First, **decide how much quality** do you want to offer to your visitors (in terms of image quality/details).

Second, if you use google analytics, you can make a list of:

- for desktop users, you can get an idea what is **the most common screen resolution** ; 
- for the mobile, almost the same (but this is a little bit complicated, **keeping in mind the device dpi** ); 

Third, you can always make responsive layouts with CSS media-queries, and of course, load different resources based on the medium the user comes from (e.g. you can load smaller images for users that come from mobile devices);

The main idea is to **serve different content, based on the user device**. And, of course, **optimize every image** to a quality level that you want to offer. If you want to spend more money on technology, you can also consider serving your content from a CDN (Content Delivery Network).

Original score: 2