How to measure page speed [plus 8 tools to try]

The faster the loading time of your website, the more positively users will experience your pages. But before you start optimizing, you first need to know how to reliably measure page speed.

Here we'll introduce you to the most important website speed tests and practical tools for doing exactly that.

What’s measured in a page speed test?

When we talk about page loading speed however, there isn’t one uniform value. A page speed test always tests a whole range of measurements that give you information about various aspects of your website speed.

In general, the loading time of a website is the time, in seconds, from when the website is called up until it is completely displayed in the browser. The terms “loading time” and “page speed” are used interchangeably.

If you search the web for the topic, you will find both variants. The loading time of a website can also be divided into 4 different measurements:

• Time to First Byte (TTFB): The time between the website being called up and the first byte loaded by the web server.

• First Contentful Paint (FCP): The time at which a display element is displayed in the browser for the first time.

• First Meaningful Paint (FMP): The time at which the user has the impression that the website is loaded.

• Time to Interactive (TTI): The time at which the website has been rendered and is ready for user input.

What affects the website speed test?

The measurements taken into account when you measure page speed depend on the bandwidth and type of connection you have. Because when the website is requested by a browser, data must be downloaded.

In general, a distinction is made between which end device is used to access the website:

• Desktop (PC or Mac): Stationary computers connected to a network are assumed to have a fast Internet connection.

• Mobile (smartphone or tablet): Mobile devices are connected to a slower 3G or 4G network.

The “latency” – in other words, the time it takes for the connection to be established between the browser and the web server – also influences the page speed. The latency is independent of the bandwidth and requires its own optimization. Important latency factors include:

Location: Depending on where your website is accessed from, the time it takes to establish a connection to the web server can vary if it is location-based.

DNS server: In order to connect to the web server, its IP address must be determined by a network of DNS servers. The duration of this discovery is affected by the number and performance of DNS servers.

The protocol used for data transmission is also important. The difference between HTTP 1.x, HTTP/2 and HTTP/3 (QUIC) matters a lot.

Important questions to ask before testing your website speed

Before you measure page speed however, there's the fundamental question of what you want to achieve.

The page speed tools discussed below each have their own uses, and some are better suited to a specific issue than others.

Questions that you can clarify with a site speed check:

• How long does your website take to load on average?

• How long does a single page on your website take to load?

• How is the loading time rated in comparison?

• Is there a measurement that appears incorrect?

• Where is there potential for optimization in terms of page speed?

• Have previous optimization measures paid off?

Website speed ​​test tools from Google

Google offers several free tools that you can use to measure your loading times. This is a clear sign of how important the topic of loading times and page experience is for the company and its search engine.

As part of its “Mobile First ”initiative, Google has geared its page speed test tools primarily to displays on mobile devices. This is a key factor for measuring the loading speed, as it’s based on a slower bandwidth, as described above.

Lighthouse (easily measures page speed in the browser)

The browser extension "Lighthouse" for Chrome should not only help to make websites faster, but also optimize aspects such as SEO and accessibility. Although the tool is pre-installed in Chrome, it's hidden among the developer tools.

To start, you must first open it with CTRL + SHIFT + I on the PC or CTRL + OPTION + I on the Mac. Under the other tools in the tab above you will find the option "Lighthouse".

Fig. 1: Page Speed ​​Tool "Google Lighthouse"

For your test, you can choose between the output for desktop and mobile, as well as the bandwidth with which you want to carry out the test. You can find the measurement of the loading speed in the “Performance” audit.

Fig. 2:  Lighthouse Page Speed ​​result

As a result, Lighthouse shows a speed score and various metrics: First Contentful Paint, Speed ​​Index, Largest Contentful Paint, Time to Interactive, Total Blocking Time and Cumulative Layout Shift.

Lighthouse's Website Speed ​​Test gives you a good overview of how quickly your website loads with different output media and bandwidths.

Page Speed ​​Insights (more comprehensive speed tests)

Page Speed ​​Insights, which is partly based on Lighthouse, provides page speed measurements for individual pages on your website.

After entering a URL, a results window is displayed that has different areas: user or field data, laboratory measurements and recommendations for optimizing the loading speed.

Fig. 3:  “PageSpeed ​​Insights” analysis result

1. Field data:  The monthly collected user data from Chrome can be found in the upper area. Google calls this area "user-side performance." These are particularly interesting as they reflect the actual user experience under real conditions and are used by Google for rankings. The Core Web Vitals values ​​Largest Contentful Paint, First Input Delay, and Cumulative Layout Shift are displayed, as well as the metrics First Contentful Paint, Interaction to Next Paint, and Time to First Byte. The measured values ​​can be explained in more detail by clicking on "Maximize view".

2. Core Web Vitals assessment: Google also shows in the user data area whether the tested site passed the Core Web Vitals check.

3. Lab data: These are the measured values ​​determined in the current speed test under laboratory conditions. They are suitable, for example, for a direct comparison after a change to the website. PageSpeed ​​Insights displays the First Contentful Paint, Largest Contentful Paint, Speed ​​Index, Time to Interactive, Total Blocking Time, and Cumulative Layout Shift metrics in this area. The measured values ​​can also be explained in more detail by clicking on "Maximize view".

4. Performance Score: With a number from 0 to 100, PageSpeed ​​Insights uses this score to summarize how well the tested page performs in the test. But beware: The performance score is calculated purely from the laboratory data and therefore does not reflect the actual loading time when visiting the website. It should therefore not be used as the sole KPI.

5. Recommendations, diagnostics and exam passes: In this area, PageSpeed ​​Insights provides hints on the causes of slow website speed and offers tips on how to improve page speed. It also shows which exams have already been passed.

Tip: You can find out how improve your loading times in our guide to page speed optimization.

Google Analytics (good for simple evaluating how page speed affects conversions)

If you analyze your website with the "old" version of Google Analytics, called 'Universal Analytics', then you’ll find loading times in Behaviour > Site Speed.

If you also have e-commerce tracking installed, you can even evaluate directly how the loading speed affects the conversions.

Fig. 4:  Check website speed in Google Analytics

(Good to know – the “new” version of Google Analytics, called GA4, omits the Behaviour tab. At least for now.)

Google Search Console (good for identifying loading issues)

In the Google Search Console you can find loading times in the crawling statistics area under the “Crawling” menu item. There you can see how many kilobytes are downloaded per day and how long the Googlebot needs to download one of your pages in milliseconds. What's particularly interesting here is the history, which makes it easier to detect loading problems, for example .

You can also find the Core Web Vitals report under Page Experience with data on performance on mobile and desktop devices.

Fig. 5:  Check Core Web Vitals in Google Search Console

More website speed testing tools

In addition to Google's solutions, there are of course other tools you can use to measure page speed. These are mostly technically oriented and offer advanced users and professionals important clues for optimizing their websites.

WebPageTest.org (the pro tool)

WebPageTest is an open source tool hosted at WebPageTest.org, among others. With this tool, detailed website measurements can be made, which are particularly suitable for technical problem analysis.

Instead of just specifying a URL, WebPageTest.org offers to define the measurement by parameters . For example, you can specify the location of the testing server and the bandwidth you want to test with. In this way, WebPageTest.org draws an individual picture of the loading speed.

Fig. 6: “WebPageTest.org” test result example

On the result page you will find various measured values, including the time to first byte . This is important to detect server-side problems or problems in the DNS configuration.

Which Loads Faster (good for comparing two websites)

If you want to compare loading times of two websites, Which Loads Faster is the right tool. All you have to do is enter the URLs of the two pages you want to compare and you can start the analysis.

However, Which Loads Faster does not offer any other diagnostics or optimization suggestions. The tool is therefore perfect for a quick comparison, but for a detailed analysis you should use another website speed test.

Pingdom.com (a good alternative to PageSpeed Insights)

The monitoring provider Pingdom.com offers an alternative to PageSpeed ​​Insights. Here, client-side factors are taken into account when measuring the page speed and options for optimization are shown.

This tool requires registration in order to use it. It shows you the loading times of your websites in the form of diagrams and statistics , which makes evaluation easier. For example, you can see very quickly which elements are preventing a page from loading.

Fig. 7: “Pingdom.com” website speed test result from wao.io

Pingdom also assigns a score that you can use for quick orientation. However, which measurement reflects the displayed "Load Time" is not precisely defined. In the overviews below, Pingdom shows how quickly individual page elements such as JavaScript, CSS and fonts were loaded.

Website speed test with Ryte

You can also use the Ryte platform to measure page speed. It provides detailed insights into the loading speed of websites.

The "Load Times" report in Ryte Web Performance not only gives you an overview of the page speed of your entire website, but also provides you with information on the time to first byte and the connection times to the server for all individual URLs.

Fig. 8: Measuring page speed with Ryte's "Load Times" report

You can also filter for the pages that have a particularly long loading time according to the page speed test (in the graph under “very slow”). This gives you extensive information about your page speed and you can find good approaches for optimization.

Under Web Performance you will also find other  reports on individual factors that can affect your page speed , such as compression, file sizes and server response. You'll also find a separate report for the Core Web Vitals with data for your entire website.

Final thoughts on how to measure page speed

When it comes to website speed testing and optimization, there are a lot of useful tools. Which of these is suitable for your own purposes always depends on what you want to achieve and how detailed the analysis data should be.

For example, the Which Loads Faster?” tool gives you just an indication of how fast your page loads compared to the competition, while with Ryte or PageSpeed ​​Insights you receive detailed information about the loading times of your pages and can easily identify optimization potentials.

With free tools you get important insights and can achieve good results. However, if you need to measure page speed more precisely, you have significantly more options with the various pro tools.

In any case, website operators should address the issue of website performance in order to increase their own website user experience and counteract high bounce rates.