Like literally anything, it will depend upon how much your code does, what libraries it uses and so on, but here's a trivial little example to at least dispell

Like literally anything, it will depend upon how much your code does, what libraries it uses and so on, but here's a trivial little example to at least dispell a worry of multi-megabyte outputs for trivial things: echo echo 1 > j.nim nim js j.nim node j.js >>> see 1\\n <<<< ls -l j.js >>> 36636 Sep 1 12:54 j.js <<< nim js -d:release j.nim ls -l j.js >>> 11369 Sep 1 12:56 j.js <<< So, with -d:release stripping away a lot of debugging logic, it's not so bad. Even with d:release there is probably ~50% of the text of that j.js that is just C comments which could be trivially stripped away. E.g., cpp<j.js|wc -c gives 6350 for that very same 11369 file. There are js minification things one could also run on the output. People do complain about this, but people complain a lot. It's probably not so uncompetitive for less trivial programs that do a little bit more work, both minified, apples-to-apples care & all that.