fasttext is one of the ones that failed for me. Too many wrongly detected languages. It's trained on Wikipedia data, not shitposts.
Discussion
It passed the "good enough" test for me, but i have really low standards
I used fasttext years ago on the Fediverse, and people complained about it a lot. So this time I'm using an obscure library I found digging through GitHub issues: https://github.com/fabiospampinato/lande
This one is specifically trained on small text, making it ideal for shitposts, but it still doesn't even take the character set into account.