What's a good basic online REPL other than Repl.it?

I used to love repl.it for throwing together quick ideas (code "sketching" as I call it), providing example code to users, etc. But over the years they've "expanded" the platform so much that nowadays you can't even use a REPL without first signing up/logging in and then waiting ~20s for a REPL to load. The wide language support is what pulled me into repl.it, as well as support for each language's package manager.

These roadblocks knock me out of my "flow" and I've resorted just using a .sketch/ directory with various language entry points with an easy way to run each of them when needed. But I miss the shareability that repl.it had.

What's a good, simple alternative to repl.it these days?