Editing Help:Preferences (section)

=== Files ===
* The images in an article are just a '''thumbnail''' (a preview). These will always be one of eight possible ''[[Help:Files#Using files|Thumbnail]] sizes''. For the larger screen sizes choose the maximum, and for the smaller screen sizes choose the minimum thumbnail size. The default 220px is a midrange thumbnail-size. Have you changed your font size? Then you should match that font size to your chosen thumbnail size to increase caption readability.

* While viewing an article, if you click a thumbnail you will activate '''''Media Viewer'''''. ''Media Viewer'' is JavaScript, and it uses processing resources. It loads all the images in the article at high resolution, and this uses networking resources. This is the default. You can turn off ''Media Viewer'' to save resources: 1) to control all image sizing, 2) to navigate directly to a file page (instead) when you click on a thumbnail.

* You can target the '''''Image size limit''''' of the ''file page'' main image, (displayed in the front matter). On a faster network choose a larger size, and on a slower network choose a smaller ''Image size limit''. The default  800&times;600px is a midrange ''Image size limit''. ''File pages'' are on Commons wiki, and if logged in there, going there overrides your settings here.

* Note that you can both turn off ''Media Viewer'' and set a small ''Image size limit'', and yet you will not limit your ability to avail yourself of any high resolution images listed at the bottom of that file page, when wanted. Doing so you can get full manual control of any unwanted, automatic bogging-down of your surfing speed caused by automated choices concerning [[wp:ns|'''File''' namespace]] interactions initiated by clicking on an image.