# Load Testing Guide

The Loadmill's Load Testing module allows users **to replay their API tests at scale** and use real traffic with the ability to target specific countries or go global.

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-a1b01880505d68c18ed72367077cf8b9dbb9dbc7%2FScreenshot%20\(26\).png?alt=media)

In this quick guide to Loadmill we will learn how to:

1. Create and run a very simple load test in just a few seconds.
2. Create an API test by using our [Chrome recorder extension](https://docs.loadmill.com/working-with-the-recorder) and run it as a load test in Loadmill.
3. Run load tests as DRY RUN or at scale.

## Let's create and run your first Load test together.

There are two ways to do that:

* Creating and running a load test from scratch in Loadmill.
* Recording an API test by using our [Chrome recorder extension](https://docs.loadmill.com/working-with-the-recorder) and running it as a load test in Loadmill.

### Creating and running a load test from scratch in Loadmill:

{% embed url="<https://www.youtube.com/embed/7Y13BkbNLpo>" %}

The simplest load test you can create is an HTTP GET request to your web server.

{% hint style="warning" %}
:brain: Load test may include **100 requests maximum**.
{% endhint %}

All you need to do is:

1. Click the **NEW TEST** button on the top navigation menu. This will get you to our test editor.
2. Give your new test a short description `My First Test`
3. Copy and paste the website URL into the **URL** text box. In our case, it's going to be `https://loadmill-test-blog.herokuapp.com`. This is a ghost blogging server we are using for testing and demos, so you can use it for tests.
4. Click the **DRY RUN** button as we recommend running your load test for the first time as a [trial test](https://docs.loadmill.com/getting-started/getting-started-1#running-a-trial-test).

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-f11f65f1c317d32a1c442ba32b3243ab93069604%2Fvideo1807115540-online-video-cut.gif?alt=media)

That's it! You have just created and run your first load test in under a minute 🎉

See how to run it at scale [here](https://docs.loadmill.com/getting-started/getting-started-1#running-a-load-test-at-scale).

### Recording an API test by using [our Chrome recorder extension](https://chrome.google.com/webstore/detail/loadmill-recorder/gdkmnfehipofdefhpegbgkkocinlaofd?hl=en) and running it as a load test in Loadmill:

1. Create an API test as explained [here](https://docs.loadmill.com/api-testing/getting-started#creating-and-running-an-api-test-by-using-our-chrome-recorder-extension).
2. Go to Loadmill and open the recorded test in your Test Suite.
3. Click on three dots next to the run icon - Click **Convert To Load Test**.
4. To run the load test for the first time, we recommend running it as a trial test. See how to do that below.

### Running a trial test

Before we run a massive load test, we usually want to run just a single iteration of the scenario, to make sure everything works as expected. This is what we call a **DRY RUN**. It's also a very easy way to test your API and can be exported to a **Functional Test** which you can later [use in your CI](https://docs.loadmill.com/integrations/npm-modal).

When we are creating a new test or extending/maintaining an old one, we like to iterate several times - modifying the test and trying it out - until we get the result we want.

To start a trial run, click the **DRY RUN** button at the bottom of the editor.

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-30e83c0b4c6f42152d42f1dfb81f0adf7a774fa8%2FScreenshot%20\(32\).png?alt=media\&token=3e34bec2-edab-486c-b351-7a47fcf4affe)

### Running a load test at scale

Now that we know that our test is configured correctly, we can run it at scale. To do that:

1. Click the **RUN TEST** button at the bottom of the test editor.
2. Set Test Duration (minutes) and **Maximum Concurrent Sessions OR Maximum Requests Per Second** you would like this test flow to run.
3. Click on **Advanced** to set additional parameters. For example, you can set **Ramp-up** **Duration** (1 minute by default) hence a number of concurrent sessions will increase linearly during the ramp-up.
4. Click **RUN**.

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-2f10ef854fd55da77065a65ccfef5e8744cea1e0%2Fvideo1399332329-online-video-cut.gif?alt=media)

{% hint style="info" %}
high-volume:man\_mage: **Note**: At some point you may notice a message stating that your domain is not *verified* - this only means that you may not run high-volume tests before proving ownership of your domain/hostname. You can learn how to do that [**here**](https://docs.loadmill.com/load-testing/setup/domain-verification) (it's actually pretty easy).
{% endhint %}

As the test progresses we can see the number of concurrent sessions **ramping up** linearly and see how **response time metrics** change over time.

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-efcd4318d547d244c46107b50e17e2c36696bf44%2Fimage.png?alt=media\&token=f2abdce7-adeb-4c82-b87e-8af0415b7de6)

In addition, you can **adjust concurrency** **during a test run**. This is a very powerful feature that allows to see how the test performs with dynamic concurrency changes in real time.

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-b22f3d851e7f33da48062178461e0133a4edae1e%2FScreenshot%20\(33\).png?alt=media\&token=6488e461-7680-4ef9-8718-146d10719801)

Loadmill keeps track of the request **error rate** and fails the test if it passes a certain threshold (%50 by default). We can see the response time for each request and are able to drill down and see the error statistics for each one.

{% hint style="info" %}
:brain: You can easily run your API Test Suite as load tests by clicking on the drop-down icon within the **RUN SUITE** button - **Run as load test**.
{% endhint %}

![](https://684333474-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LHDbUNdi3wPd9vSolzU%2Fuploads%2Fgit-blob-fa3a11e4a60aad2ca9b13c47701eefaf44341b2e%2Fvideo1977598869-online-video-cut%20\(1\).gif?alt=media)

Keep exploring the guides to learn how to analyze load test results, set thresholds and more.

### Support

We are always here if you need any help! Click on the bubble chat button in the lower-right corner of the screen or drop us a line at <support@loadmill.com>.