Does anyone know how iOS Safari 9 handles page crashes or freezing?
Apple engineers wrote the code, but it's not available for inspection so the larger context is yes there is a system but we don't get to see it.

You can look at the logs an iOS device generates by plugging it into Xcode on a Mac or the Apple Configurator. If you do that, you will see that when an application crashes entirely - there will be a log file (that optionally is sent to Apple) explaining what crashed on a technical level.

The second level of logging is when an app (Safari in this case) burns too much CPU. This is likely what you want - when a web page has excessive javascript, buggy javascript, continual tracking and acts more like a program than a short document to be rendered once - you will get a spin dump that again is mostly engineering data - but you will know the OS noticed the app was nor behaving like a short, quick efficient worker. The have spin in the file names.

Lastly, you can avail yourself of the well documented and very powerful Safari development tools by enabling debug and inspecting what Safari is doing on an extremely granular level to include errors, warnings, code inspection, timing to the millisecond, etc...


https://developer.apple.com/safari/tools/