You track the performance of your website: visits, page views, bounce rate, etc.? But are you on the lookout to know in real time what needs to be optimized on your pages to maintain an optimal user experience? Images that are too heavy, JavaScript out of control, server response time that is too long… If your pages are slow, you risk degrading the quality of the user experience on your website, and this speed problem can affect your conversion rates and your SEO. Here are some tips to prevent and remedy the impression of slowness on your site.
Slowness doesn’t only happen to other people
On an e-commerce site, a loading time problem can have a negative impact on your business and marketing results. If your site is slow, unfortunately, your turnover suffers. The speed of web pages is even the main UX requirement for 75% of mobile users, and 53% do not wait more than 3 seconds for a page to load (Google study). Beyond that, they leave your website, go to your competitors and do not come back.
A study by the Digital Fuel agency reveals, for example, that on mobile, 1 second of additional loading time results in:
- -7% conversions
- -11% of page views
- -16% customer satisfaction
You can’t take this risk for your turnover, nor for your image! Indeed, your users will not hold back from publicly expressing their dissatisfaction or ordering from your competitors if your website does not respond or if it is too slow.
Also, if you think that a speed problem can only happen to others, think again. Even giants of global e-commerce have already had the bitter experience of sites being unavailable or significantly slowed down during major commercial events that cause load peaks . This is the case of the retailer Gap whose pages needed 30 seconds to load on Black Friday 2017 (due to an integration problem with Snapchat); or the merchant site of the H&M brand, unavailable for more than an hour on the same day. In 2018, Amazon Prime also suffered a 63-minute interruption during “Prime Day” – estimated losses: $99 million .
In light of the figures presented above on the impact of loading times on marketing KPIs, you will have understood: this problem of slowness and these malfunctions have necessarily generated a significant loss of earnings.
What causes a slow website?
Concretely, what can cause a drop in performance and an increase in loading times? The source of the problem can be all the more complex to identify if a website contains or uses many resources to display on a browser: images, dynamic content called from external databases, third-party scripts , CSS and HTML files, etc.
Be aware that in 2023, on all the pages analyzed by the HTTP Archive site, an average web page generates approximately 70 requests ; and according to this same site, nearly 50% of the pages analyzed on mobile that contain JavaScript include at least one that presents a vulnerability .
Thus, resources that are too heavy or poorly optimized (images, HTML files, CSS, JavaScript), a saturated server or security flaws can be the cause of a loading time problem. And these are only the most common causes of a degradation in speed, or even the unavailability of a website.
Identify and anticipate abnormal performance on a website
You can detect performance anomalies on your web pages using alerting tools such as SpeedCurve or Pingdom .
Using these monitoring tools , you can be notified in real time if the speed of your pages deteriorates, in order to intervene as quickly as possible in the event of an abnormal slowness problem.
Be careful, not all performance drops are necessarily anomalies as such. Obviously, you must be able to identify weak signals, but there is no question of overloading yourself with alerts because that would be counterproductive.
But then, how do you estimate from how many seconds or milliseconds of additional loading time you should intervene?
Let’s get the mystery out of the way right away: there is no single answer that would be valid for all websites. To help you find your way around, here are some suggested methods.
Locate yourself based on your performance history
To define the alert thresholds that will allow you to react in real time, observe your performance over time and note the most significant variations in indicators. Then set your alerts as soon as you exceed these thresholds.
Set a Performance Budget
For effective long-term work , set a Performance Budget : define scores to reach (for example, a PageSpeed score ), thresholds not to exceed (webperf metrics, page weight, number of requests, etc.), or a place to reach in the monthly JDN webperf ranking . As soon as your score drops, you exceed these thresholds or you lose places in the ranking, it is a sign that it is time to act. Note that a Performance Budget can be confronted during all phases of development of your site, by including it in a continuous integration.
In terms of KPIs, you can focus on performance indicators such as Speed Index , Start Render / First Contentful Paint or Time To First Byte … Be careful, do not rely on Load Time , it indicates the time needed for a page to load completely, but it is not necessarily representative of the user experience. But also on those that Google takes into account to evaluate the user experience such as Largest Contentful Paint , Cumulative Layout Shift and Interaction to Next Paint . These are the Core Web Vitals that the search engine integrates into its SEO algorithm to rank search results since its Page Experience update .
Obviously, there is no such thing as zero risk, but setting up safeguards upstream and anticipating will protect you from as many unpleasant surprises as possible. Here are some examples to follow:
- Uni-Médias has set a maximum weight of 2 MB for the pages of its press sites (including advertisements) and intervenes as soon as this weight is exceeded.
- Le Parisien systematically tests the impact of new features on the speed of its pages before putting them into production, and continues monitoring once they are deployed.
- The retailer King Jouet has fully automated its webperf optimizations in order to have a fast site all year round, and relieve its servers during traffic peaks. The e-commerce site thus remains available and fast during promotional periods.
- Furniture specialist But has opted for automating the speed of its pages, so that the site remains fast at all times while relieving its technical teams. Thanks to our Next Generation CDN , it also benefits from an additional layer of security .
- Trigano Store also secures its turnover , especially during private sales which can generate up to 20 times more traffic, by automating the optimization of the speed of its pages.
But no matter how much you prevent, sometimes you have to cure.
Slow or unavailable site: what to do
If, despite your efforts, you identify an abnormal degradation in the display speed of your web pages, here’s what to do:
- identify who is impacted by this anomaly: geographic area, browser, support, network, etc.,
- List the pages of your website that are affected,
- look at the delta compared to the usual performance of these pages
- Optimize or fix the resource(s) responsible for the slowness issue .
In the event that the anomaly is caused by a third party:
- check the publisher’s support and follow the instructions to get your third party back in line,
- If you are unable to restore normal operation, disable the third party to allow your visitors to continue their journey and purchases.
Example of visualization of a particularly time-consuming resource using the WebPageTest tool which generates a graphical representation of the loading of elements on a web page
As we mentioned: anticipating means ensuring your peace of mind.
So, to prevent Third Parties from slowing down your web pages in the event of a malfunction, here are some tips to apply to your website pages:
- prioritize loading and execution of scripts so that they do not degrade interactivity;
- Build in timeouts on your pages – this way, in the event that third parties do not respond, your visitors will still be able to continue browsing.
Keep a fast site everywhere, all the time, in all circumstances
As we have seen, poor loading times are a danger for your business, your image and your SEO at any time of the year, but the risk is even greater during promotional periods. If your site is slow or unavailable during Black Friday, Cyber Monday, Sales, Christmas or private sales… the loss of earnings is even greater!
So, to avoid your site being slowed down or completely unavailable in the event of high traffic, especially at crucial times for your turnover, prepare the ground with fast pages, and be ready to react instantly in the event of an alert. In 3 key points:
- Monitor your performance , and use real-time speed monitoring and alerting tools.
- Manage and prioritize your Third Parties.
- Provide an overflow page , so your users know that they have to wait if your site is temporarily unavailable, and that they can finalize their order a little later.
- Optimize the speed of your web pages to provide a smooth experience to all your visitors in all circumstances, regardless of the device and network quality, even during peak loads. To save time and resources, consider automating best practices and acceleration techniques (that’s what our engine does ;)).
To go further and understand how to
measure and analyze the speed of your web pages: