I don't know if this is already known but i wanted to explain it to everyone in a topic.

For example, let's say that we have downloaded an image from Furaffinity many years ago and it still has the same name it originally had.

Example:https://imgur.com/a/O6p5E5s

Copy the name of the file starting from including the artist's name and excluding the file format..

delete anything that isn't a letter or a number
also delete non-ascii characters and possibly letters from the cyrillic/asian alphabets, if there's any of them

so the file title:

1300467759.narse_larus_birthday_2011_b.png

becomes

narse larus birthday 2011 b

type it in the search bar and you'll get the precise submission hosting that file
final result: https://imgur.com/a/RYw32IL

Of course it won't work if the original submission was deleted or the account has been deactivated.