Postman: How to make multiple requests at the same time

Not sure if people are still looking for simple solutions to this, but you are able to run multiple instances of the "Collection Runner" in Postman. Just create a runner with some requests and click the "Run" button multiple times to bring up multiple instances.

Run all Collection in a folder in parallel:

'use strict';

global.Promise = require('bluebird');
const path = require('path');
const newman =  Promise.promisifyAll(require('newman'));
const fs = Promise.promisifyAll(require('fs'));
const environment = 'postman_environment.json';
const FOLDER = path.join(__dirname, 'Collections_Folder');


let files = fs.readdirSync(FOLDER);
files = files.map(file=> path.join(FOLDER, file))
console.log(files);

Promise.map(files, file => {

    return newman.runAsync({
    collection: file, // your collection
    environment: path.join(__dirname, environment), //your env
    reporters: ['cli']
    });

}, {
   concurrency: 2
});

In postman's collection runner you can't make simultaneous asynchronous requests, so instead use Apache JMeter instead. It allows you to add multiple threads and add synchronizing timer to it

If you are only doing GET requests and you need another simple solution from within your Chrome browser, just install the "Open Multiple URLs" extension:

https://chrome.google.com/webstore/detail/open-multiple-urls/oifijhaokejakekmnjmphonojcfkpbbh?hl=en

I've just ran 1500 url's at once, did lag google a bit but it works.

Easiest way is to get => Google Chrome "TALEND API TESTER" Go to help + type in Create Scenario ...or just go to this link => https://help.talend.com/r/en-US/Cloud/api-tester-user-guide/creating-scenario

I was able to send several POST API calls simultaneously.

You can run multiple instances of postman Runner and run the same collection with different data files in each instance.