Messenger's own search feature is pretty bad (can't search far back into history, matches common words I don't want to match, can't use regular expressions, etc.). I think it wouldn't be hard to write a script that uses the Facebook data export to search for messages.
I tried looking for something like this a while back but couldn't find anything.
i think the exports are somewhat better these days. i've also gotten better at storing things in more searchable places so haven't needed to look things up much in messenger.
Messenger's own search feature is pretty bad (can't search far back into history, matches common words I don't want to match, can't use regular expressions, etc.). I think it wouldn't be hard to write a script that uses the Facebook data export to search for messages.
I tried looking for something like this a while back but couldn't find anything.