, instant REPL built by Raynes

I decided to reinstate the simple online REPL that Raynes created:

This is a Clojure/Java equivalent of the ClojureScript/JavaScript REPL at

There are many online REPLs that are more sophisticated than this (with editors attached, saved session history, sharing, etc), however for the instant evaluation of an expression that beginners sometimes want, without a sign-up and without a complex UI, I think there’s something nice about Try Clojure. I also like seeing Anthony Grimes’s work live on in this way.

I made some very minor changes to update dependencies, add TLS support and improve the way idle sessions time out (fixing this bug). There are no doubt some ways to break this site, but it uses Clojail and an execution time limit to minimise the risk (similar to 4Clojure). It probably depends a bit on good will too.

The old domain was tryclj, but this is an ad farm now and appears to have a price tag over $2,000.

So please feel free to share this and link to it wherever you would have linked to the old site. If you come across a link to, please update it to


Thank you so much!