When switching between tabs in Safari Mobile — Even within a few seconds — Safari will automatically reload the tab.
This will happen more frequently between sessions: Switching between Safari Mobile to another app and back will cause every open page ("tab") to reload.
Not long ago, I found a tutorial explaining how to prevent Safari Mobile from reloading tabs while browsing that involved plugging in the iPhone, and making use of Safari Desktop's Development Web Inspector, similar to the method viewable in this tutorial: http://appletoolbox.com/2014/05/use-web-inspector-debug-mobile-safari/
To prevent the Mobile app from reloading tabs by default. However, the above tutorial is only for troubleshooting how a specific webpage appears on the iPhone, and I can no longer find the tutorial to prevent Safari from reloading all tabs each session.
Solutions tried have included:
Closing all other apps
Clearing History and Website Data
Restart
Changing Settings > Safari > Open Links from "In Background" to "In New Tab"
Resetting Network Settings
Clearing available storage space
Reset All Settings
Restore phone from backup
Tabs still reload. This is commonly attributed on the Apple Support and other threads I have read to "Memory Issues" or default behavior for "Memory Allocation":
http://forums.imore.com/ios-8/302019-safari-stop-reloading-my-pages.html
http://forums.macrumors.com/threads/sick-of-safari-reloading-pages.1807865/
http://www.reddit.com/r/ipad/comments/2gv2rb/does_ios_8_fix_the_constant_tab_reloads_in_safari/
Yet pages are visible and usable in the tab immediately after switching, but then reload anyway. Not good in poor coverage areas.
Is anyone aware of a true solution to prevent this automatic reloading behavior in Safari Mobile?
Best Answer
As you have read, this is down to memory management. iOS will remove background tabs from memory when that memory is required for something else. The device you're using is more significant than the version of iOS. An iPhone 6 with 1GB of RAM will close tabs more aggressively than an XS with 4GB.
As others have mentioned in the comments, iOS keeps a thumbnail of the page in memory so that you know which tab is which. This thumbnail requires much less memory than a full web page rendering context.
Reclaiming memory used by inactive apps/tabs is actually a feature. You wouldn't wan't an app to fail to launch because your phone is out of memory, so iOS automatically makes space for it. For the same reason it's not necessary to "close" apps, as iOS will remove apps from memory when necessary.
Apple doesn't include RAM in the specs published for iOS devices, but wikipedia has a handy summary of iOS device specs.