Which memories are deleted first?

This surprises most people, and it is worth reading twice because it changes what you should be worried about. Intuition says the oldest goes first, like a bin emptied from the top, or like a phone that deletes the photos you have not opened in years. Snapchat has described the opposite: the oldest snaps are kept, and it is the content sitting above the 5 GB limit that is removed.

In practice that means your memories from school may be safer than what you saved last year. It is not a guarantee, it is how the rule has been described, but it is worth knowing before you decide what is urgent. If most of what you actually care about was saved recently, you are closer to the edge than the intuitive version of the rule would suggest.

What it does not mean: that you can relax because your most important memories are old. The limit applies to the total, and you have no say over exactly which files count as being "above" it. It is not a list you can go through and prioritise. Snapchat has not published which of your files sit on which side of the line, and there is no screen in the app that shows you one, so there is nothing to review and nothing to rescue individually.

The only method that gives you real control is to get everything out and keep it yourself. Then it makes no difference which end Snapchat counts from, because you have the whole archive either way. Once it sits on your own drive the question stops being interesting: nothing is queued for deletion, so nothing has to be ranked.