How to force parse request body as plain text instead of json in Express?

By default bodyParser.text() handles only text/plain. Change the type options to include */json or */*.

app.use('/some/route', bodyParser.text({type: '*/*'}), function(req, res) {
  var text = req.body; // I expect text to be a string but it is a JSON
});

//or more generally:
app.use(bodyParser.text({type:"*/*"}));

You can find the docs here