One notable difference between Elm and Clojurescript in general is that Elm has very limited interaction with the whole front end ecosystem, where as in Clojure

One notable difference between Elm and Clojurescript in general is that Elm has very limited interaction with the whole front end ecosystem, where as in Clojurescript you can do anything that the JavaScript guys could do. Elm's ports don't really do much in that area. Clojurescript respects developers to access all the power that browsers can offer you, if you want it. Another big difference is that Clojurescript can be passed through advanced optimizations, but Elm does not support those. But in Clojurescript, most projects are already setup for optimization out of the box. This is the same optimization that Google uses for all of its services such as Gmail, Google.com, etc. And it is industry-leading. The final notable difference is that most work in Clojurescript uses figwheel, which greatly accelerates front end development with it's automatic reloading of what you work on as you save it, as well as other information it provides. Elm has attempted something similar, but it's quite limited and doesn't support a lot of the complex stuff you might want to do in Elm, and Elm's documentation says only to use it for basic tasks. There is also the re-frisk tool for re-frame which gives you super easy visual inspection of your entire application state in a graphical tree, quite useful. All that said, Elm as a language is very attractive. But as an advanced development platform, it doesn't go nearly far enough. Perhaps one day it will.