ngrok – Secure Tunnels to localhost

When you are developing an application that includes webhooks (Slack, OKTA, etc) you need a publicly accessible URL to connect the webhook service with. Usually you develop on localhost and there is no access for someone else to it. So, how can you test your webhooks in such situation?

Let’s introduce ngrok.

ngrok is a free tool that allows you to expose a web server running on your local machine to the internet. It includes additional functionality that makes it easy to install and manage itself as a native operating system service on Windows, OS X and Linux.

ngrok schema

There is a step-by-step guide that helps you configure ngrok on your computer with Mac OS.

  1. Download the ngrok version corresponding to your platform from the official source
  2. Create a folder on your computer and unzip ngrok. In my case this is:
  3. My local domain is
  4. Run a command below to assign it to ngrok:
    /Users/developer/ngrok/ngrok http -host-header=rewrite
  5. As a result of the command execution, you’ll see something similar to: Command to initiate ngrok
  6. You may see that my local domain has been transferred into external And you can open it in your web browser:External domain in web browser

ngrok provides a real-time web UI where you can introspect all of the HTTP traffic running over your tunnels. After you’ve started ngrok, you can open in a web browser to inspect request details:

ngrok web interface

It is clear that ngrok is really easy to install and use. In this post I’ve given basic information for you to use in your development process. You can find more ngrok features in the documentation.