This is a playground to test JavaScript. It runs a completely standard copy of Node.js on a virtual server created just for you. Every one of npm’s 300,000+ packages are pre-installed, so try it out:
var express = require("@runkit/runkit/express-endpoint/1.0.0");
var bodyParser = require('body-parser');
var app = express(exports);
app.use(bodyParser.text({}));
app.post("/", (req, res) => res.send(encodeURIComponent(req.body)));