Well, it really depends on the context. Take this one:
https://httpstatusdogs.com/304-not-modified
I'd surely crack that joke with close friends, but at work I would absolutely not risk that, especially if I don't know whether the receiving party has a similar humor. Compare that with http.cat:
https://http.cat/304
It's a cute picture of cats. It might get an eyeroll, yes, but nobody is going to accuse me of an inappropriate joke for that. 226 is even worse and I know quite a few female colleagues which would probably not take it well, irrespective of it being a picture of a dog.