What is the highest Ruby version supported by Rails v4.1.16?

Question

In other words, can I run Rails 4.1.16 on Ruby 2.4? If not, can I run it on Ruby 2.3?

Answer 1

Based on the CI settings for 4-1-stable, I'd say stick with Ruby 2.3. 2.4.0 isn't on that list, as things stand.

That's not to say that 4.1.16 won't run on Ruby 2.4 - I can't really speak to that - but there's always a possibility that you hit subtle issues, depending on the features you use and the gems that you include. Ruby 2.4 has the Fixnum and Bignum unification, as well as unicode changes - which potentially could have an impact.

FWIW, we have a sizeable, battle-tested application on the 4.1.x branch that works just fine on Ruby 2.3.3.