The speed of web pages is essential for the user experience and SEO. One of the tools for testing the performance of web pages is WebPageTest. In this article, we will look at what WebPageTest is, how to use it to test the performance of web pages, and how to interpret the test results.
What is WebPageTest
WebPageTest is a tool for testing the performance of web pages. It allows you to measure the page loading time, data transfer speed, network usage, and browser resources and detect possible problems in the page code that may slow down its loading.
How does loading time affect user behavior?
Marketing specialists of the analytical platform KISSmetrics conducted a study on the distribution of user attention and came to the following conclusions:
- If the user cannot interact with a site or application within 6-10 seconds, he will leave.
- The conversion rate decreases with every second of delay.
- 10% of people wait until two seconds.
How does loading speed affect sales and conversion?
- One-second delay reduces conversion by 7%. If the site earns $ 100.000 per month, increasing the page loading speed by one second can bring up to $ 7.000 monthly.
- Mozilla noted 60 million more downloads after speeding up its web page by 2.2 seconds.
- Amazon has estimated that slowing down loading speed by just one second could cost $1.6 billion annually.
In order not to incur losses or, conversely, to increase profits from the site or application, you may consider testing performance.
How to use WebPageTest?
To use WebPageTest, you need to go to the official website of the tool: https://www.webpagetest.org/
On the main page, you will see a field for entering the URL of the page you want to test. Here you can select the server’s location where you’d like to run the test.
After entering the URL and selecting the server, click the “Start Test” button. The test will take a few minutes. Then you will receive detailed information about the performance of the page.
Interpretation of test results
WebPageTest provides a lot of data about the performance of the page. Some of the most critical metrics that need to be analyzed are:
- Page Loading Time: The time it takes to load the entire page. The shorter the time, the better.
- First Byte: The time it takes for the server to send the first byte of data. The optimal time is less than 200 ms.
- First Paint: The time it takes to display the first image on the page. The shorter the time, the better.
- Fully Loaded Time: The time it takes to load all the resources on the page entirely. The optimal time is less than 5 seconds.
- Requests: The number of requests sent to the server to load the page. The smaller this number, the faster the page will load.
- Bytes In: Page size in bytes. The smaller the size of the pages, the faster they will load. The optimal page size is less than 1 MB.
In addition to these metrics, WebPageTest provides information about how the page loads in the user’s browser using tools such as Waterfall Chart and Filmstrip View. Waterfall Chart displays the loading time of each element on the page, including images, CSS files, JavaScript files, etc. Filmstrip View shows how the page is displayed to the user as it loads.
WebPageTest also can compare the performance of two or more pages. It can be useful to compare the performance of pages of different versions of the site or your site’s performance with competitor sites.
In conclusion, WebPageTest is a powerful tool for testing the performance of web pages. It allows you to get detailed information about the page loading time, network usage, and browser resources, as well as to detect possible problems in the page code that may slow down its loading. Using WebPageTest can help optimize your website and improve the user experience.
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