Step 1 - Enter the target page URL in the top/left box:
Step 2 - Type the number of retries (if you want the tool to download the target page more than 3 times)
Step 3 - Click the "Test" button and wait some time (depending on the number of retries you entered, the site speed, the internet connection speed).
That's it. You can see the average speed in the yellow box now.