Selenium IDE Measurements plugin - Web Performance

Selenium IDE Measurements plugin

This plugin for Selenium IDE allows collection of performance measurements during a test.


This Selenium IDE plugin can be installed in Firefox as an extension directly from the Firefox Add-ons store.



The plugin adds new commands to start and stop timers. Each timer has a name.

To start a timer:

start timer | <name>

To end a timer:

end timer | <name>

You can download this example .side file to get started. After downloading, you can open it with Selenium IDE and then run it to collect measurements.

Viewing the measurements

As the test runs, the measurements from the timers are collected and stored in the plug-in. To view the measurements, press the  button in the Firefox toolbar. After running the test shown above three times, you would see:

Exporting the measurements

The JSON and CSV links under each test provide an export of the measurements. The CSV data can be easily pasted into a spreadsheet and graphed. The JSON format is the internal representation and contains additional information that may or may not be useful such as the TestID and RunID assigned by Selenium IDE. Note that the JSON format is subject to change without warning and absolutely no effort will be made to maintain compatibility with previous versions.


Within a single run of a test, the logic may include looping. The Measurements plugin takes a very simplistic approach to detecting iterations: when a measurement has a name that already exists in the current iteration, a new iteration is started. This works well if all the measurements of interest are in that loop. Such as when the entire test exists within a times loop – this could be used so that a single test run in the IDE exercises the test steps multiple times to gather more performance data (possibly to use average durations to lessen random noise). In this case, the lines will be numbered 1.1, 1.2 … 1.N where N is the number of times the test loops. Subsequent runs would be numbered 2.1, 2.2 … 2.N.

Need help?

You can click the Have a Question? tab in the upper-left of this page, or go open a support ticket.

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