---
title: "Running Instant Tests"
slug: "instant-tests"
updated: 2026-09-16T14:01:04Z
published: 2026-09-16T14:01:04Z
canonical: "docs.catchpoint.com/instant-tests"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.catchpoint.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Running Instant Tests

Catchpoint’s WebPageTest Instant test is based on our popular [WebPageTest.org](https://www.webpagetest.org/) platform, and enables you to perform the same types of tests instantly from within the Catchpoint Portal. The WebPageTest Instant Test has most of the same configuration options as the website, so if you are familiar with that platform, it should look pretty familiar. This guide will walk you through submitting a test and interpreting the results.

## Running an Instant Test

Follow these steps to run a basic performance test using default settings.

1. Log into the Catchpoint Portal
2. In the main menu on the left, select **Instant Tests**
3. Click **New Test**
4. Input the URL of the web page you want to test in the **Enter Website URL** field
5. In the **Device** field, select a predefined Device, Connection and Dimension combination or select **Customize** to select other options.
6. Select the **Location** (node) to run the test from  

a.	Either select one of the locations listed  

-or-  

b.	Click **Other Locations**, then locate and select the desired location
7. Click **Run Test** to execute the test. The results will be available once the test completes, which may take several minutes depending on the website you are testing and the settings selected.

#### Test Parameters

- **Connection** – specifies the type and speed of internet connection you want the test to emulate.
- **Browser Dimension** – when testing using a Desktop browser, this setting lets you specify the dimensions of the browser window used to test the web page.
- **User Agent String**
  - **Preserve Original UA String** – Uses the original User Agent string without the WPT suffix, which provides information to the website about the connecting device and browser
  - **Append to UA String** – specify additional text to append to the user agent string
  - **Custom String** - specify a fully customized user agent string
- **Number of Runs** – the number of test runs to execute for this Instant Test. By executing multiple test runs, you will get a wider sampling of web page performance.
- **Repeat View** – causes the page to be loaded twice during each Test Run.
- **Tests Performed** – choose Performance, Lighthouse, or both.
  - **Performance** - captures detailed site performance metrics including [Core Web Vitals](https://web.dev/articles/vitals).
  - **Lighthouse** - [Google's open-source initiative](https://developer.chrome.com/docs/lighthouse/overview/) for auditing the performance of any web page.
- **Label** – you can assign one or more labels to the test, which makes it easier to find specific test results later.
- **Notes** – you can enter any information you want saved with the test results.

#### Advanced

- **Test Duration**
  - **Min test Duration** – specifies how long the test will take at minimum. This way, even if the initial page load has completed, the test will continue to watch for any additional activity up to the minimum duration.
  - **Stop Test at Document Complete** – when selected, the test will terminate at Document Complete, regardless of the minimum duration setting.
- **Capture Settings**
  - **Full Size Video** - when enabled, test results will include a full-size video of the browser rendering the webpage.
  - **Network Packet Trace (tcpdump)** - when enabled, test results will include a tcpdump.
  - **Response Bodies for Text Resources**- when enabled, response bodies will be displayed under Request Details in Waterfall.
- **Image Support**
  - **Disable AVIF image support** - do not load AVIF formatted images
  - **Disable WEBP image support** - do not load WEBP formatted images
- **Custom Headers** - include a custom header with all requests generated by the browser during the test
- **Inject Script** - include a custom javascript which will run after the page loads

#### Security

- **Authentication**
  - **Basic** - Configures HTTP Basic Authentication credentials for single-URL tests via the standard authentication interface.  

⚬	Username: The basic authentication username.  

⚬	Password: The basic authentication password.  

⚬	Scope: Applies specifically to the target test URL defined in the single-page configuration.
  - **WPT Script** - Configures global authentication credentials and target domains for multi-step or complex custom test scripts.  

⚬	Username: The username exposed to the test script via the %USR% variable.  

⚬	Password: The password exposed to the test script via the %PWD% variable.  

⚬	Domains: A list of target domain names allowed to receive these credentials.  

⚬	Script Usage: Dynamically references %USR% and %PWD% within script steps (e.g., setting input field values or headers) to avoid hardcoding sensitive credentials.
  - **Discard All HTTP Headers** - select to remove all HTTP headers from test results
  - **Ignore SSL Certificate Errors** - when loading the webpage, disregard any SSL certificate errors

#### Chromium

- **Chromium Test Parameters**
  - **Run Carbon Control**- when selected, your website's carbon footprint will measured.
  - **Use Chrome dev tools traffic shaping** - can be used to emulate different internet connection characteristics. We recommend using the settings available in the **Advanced** tab.
  - **Host Resolver Rules** - one or more hostnames and the IP address(es) you want them to resolve to. Settings here will bypass DNS lookup for the specified hosts.
  - **Command Line** - additional Chromium command line switch(es) to customize test behavior.
- **Capture Settings**
  - **Capture Dev Tools Timeline** - when enabled, test results will include the Chrome DevTools timeline trace.
  - **Capture Network Log** - when enabled, test results will include a HAR file listing all network requests.
- **Trace Settings**
  - **Capture Chrome Trace** - when enabled, test results will include Chrome Trace.
    - **Trace Categories** - a listing of the trace categories to include in the Trace.
  - **Enable V8 Sampling Profiler** - when enabled, the log file will include a sampling of javascript activity that occurred during the test. This results in much larger trace files.
  - **Capture V8 Runtime Call Stats** - when enabled, test results will include certain low-level V8 metrics which aren’t currently exposed in DevTools.

#### Script

• **Script** - Enable/Disable including a test script • **Script includes sensitive data** - select this option to omit the script from test results

#### Block

• **Block Requests Containing URL Substrings** - specify a list of substrings and the test will block requests containing any of them • **Block Domains Full Host Name** - specify a list of host names and the test will block requests to any specified hosts

#### SPOF

• **Hosts to fail** - use this setting to simulate failure of specified domains. All requests for the domains will be rerouted to blackhole.webpagetest.org which will silently drop all requests.

#### Custom

WebPageTest can execute arbitrary javascript at the end of a test to collect custom metrics. These can be defined statically in the server configuration or be specified at runtime on a per-test basis.

[The HTTP Archive](https://httparchive.org/) uses WebPageTest custom metrics to power their reports, as well as the analysis in the [annual Web Almanac](https://almanac.httparchive.org/en/2025/). The metrics are all available in a [public GitHub repository](https://github.com/HTTPArchive/custom-metrics) if you would like to dig in and get some ideas for what's possible.

The javascript should be written as if it were executing inside of a function call and return the custom metric at the end. Here is an example that finds the meta viewport for the page and extracts it:

```
var viewport = undefined;
var metaTags=document.getElementsByTagName("meta");
for (var i = 0; i < metaTags.length; i++) {
    if (metaTags[i].getAttribute("name") == "viewport") {
        viewport = metaTags[i].getAttribute("content");
        break;
    }
}
return viewport;
```

**Supported Browsers**

- Internet Explorer
- Chrome
- Firefox

#### Things to watch out for

- Asynchronous operations are supported by returning a Promise, but it must resolve after 30 seconds.
- Custom metrics live in the same namespace as the built-in metrics and can override built-in metrics if they have the same name.
- Metric names should be simple alpha-numeric and probably without spaces.

#### Specifying custom metrics at test time

The text input box for the metrics takes the metrics definitions in the form of an ini file for simplicity:

```
[metric-name]
<code>

[metric-2-name]
<metric 2 code>
```

Here is an example that collects 3 different metrics (2 numerical and one string):

```
[iframe-count]
return document.getElementsByTagName("iframe").length;

[script-tag-count]
return document.getElementsByTagName("script").length;

[meta-viewport]
var viewport = undefined;
var metaTags=document.getElementsByTagName("meta");
for (var i = 0; i < metaTags.length; i++) {
    if (metaTags[i].getAttribute("name") == "viewport") {
        viewport = metaTags[i].getAttribute("content");
        break;
    }
}
return viewport;
```

#### Bulk Testing

Allows you to run performance tests across multiple URLs simultaneously using the configured test settings.

- ***Bulk Testing*** Enables or disables multi-URL input for the test run.
- ***URL Input Field*** Accepts multiple target URLs entered one per line. When enabled, this field overrides the single URL input.
- ***Import Text File*** Allows uploading a .txt file containing a list of target URLs (one per line) directly into the test setup.
- ***Execution Behavior*** Submits tests in batch. Once initiated, you are redirected to the Test History page to view and select individual test results.