After version v12.17.0, Node’s REPL provides a preview effect. In this example, if we type 1 + 1, Node shows us the result in gray before before hitting enter:

> 1 + 1
2

But what if I don’t want that? Here’s a script called repl that disables it as an option:

#!/usr/bin/env node

const repl = require('node:repl');
repl.start({preview: false});

When we start Node via this script, we disable the preview:

$ ./repl
> 1 + 1