4chan has global rules and board-specific rules.
Racism, hate speech in general, as well as anything illegal, will quickly result in deletion and IP ban.
The site will also, as it's obvious, cooperate with authorities, when it comes to crimes.
4chan is far from being a free-speech absolutist site.
But it has much less of a barrier to post things. You do not need an email or a phone number you can just post. And an IP ban will only be effective to prevent the average user. Still though things get removed and moderated and I am okay with that. Having seen some of the telegram groups and the misinformation they spread was a crazy eye opener during covid times.