stsyn
Moderator
There is an autocomplete function in almost all browsers (Derpibooru itself doesn’t save your search history), and sometimes it resets. If you have a some kind of “junk clearing app”, it may remove autocomplete data as “non-critical data you’ll never use next time”.
So, if you didn’t accidentally switched users or used incognito mode — I don’t know a way to get them back.
So, if you didn’t accidentally switched users or used incognito mode — I don’t know a way to get them back.