In the world of web design, sliders, also known as carousels and "rotating banners," have long been a popular element for presenting multiple pieces of content in a small space. However, a thorough analysis, from both a web performance and user experience perspective, reveals significant drawbacks.
This article aims to examine in detail why sliders should be avoided in modern website design, particularly considering their impact on accessibility, user experience, web performance, and eco-design.
By adopting a holistic perspective and drawing on recognized data and practices, we will demonstrate why it is time to rethink the use of sliders in web design, for the benefit of users, businesses, and the environment.
Sliders and accessibility: a difficult coexistence
Digital accessibility is a fundamental element in website design, aiming to make digital content usable by everyone, including individuals with various types of disabilities, such as visual, auditory, motor, and cognitive. The use of sliders (carousels) on websites poses major challenges in terms of accessibility, negatively impacting this inclusive approach.
Neurological Disorders
Flashing or moving content, often characteristic of sliders, can trigger seizures in people with photosensitive epilepsy. Beyond this risk, these elements are generally considered annoying for the majority of users, highlighting how accessible web design and a good user experience are intrinsically linked.
Motor Disabilities
Sliders can pose particular difficulties for people with physical disabilities who use assistive technologies to navigate the web, such as voice commands or eye-tracking software. These tools generally have difficulty controlling the interactive elements of sliders, such as navigation or pause buttons.
Compliance with Web Accessibility Standards
Sliders often pose challenges in complying with international web accessibility standards, such as the WCAG (Web Content Accessibility Guidelines) developed by the W3C (World Wide Web Consortium). The Web Accessibility Initiative also dedicates a tutorial to this, with concrete recommendations to facilitate access.
These guidelines are structured around four principles: perceivable, operable, understandable, and robust. Sliders, by their very nature, can violate these principles by making content difficult to perceive, operate, or understand for users with specific needs.
Sliders and User Experience: A Counterproductive Choice
The use of sliders or carousels on websites has a considerable impact on user experience (UX), an aspect crucial for a site's success. Although the intention behind integrating sliders is often to make the site more dynamic and attract user attention, their actual impact can be quite different, significantly influencing user engagement and satisfaction.
Low Interaction and Click-Through Rates
Sliders are often perceived as an effective way to present multiple messages or products. However, studies show that users interact little with these elements.
In reality, the majority of clicks are concentrated on the first slide, with a significant drop-off for subsequent ones. This phenomenon is often attributed to "banner blindness," where users instinctively ignore elements they associate with advertisements, as is often the case with sliders.
Readability Issues and Cognitive Overload
Sliders pose challenges in terms of readability. Automatic scrolling, in particular, can disrupt the user's ability to read and absorb information, creating a frustrating user experience. This frustration is exacerbated when a user tries to read text on a slider that changes before they have finished.
Furthermore, the presence of multiple messages in the same space can lead to cognitive overload, making it difficult for the user to focus on a specific piece of information or action. Finally, there is sometimes chaotic support for certain types of devices (especially tablets), leading to interfaces that are even less readable for some users.
Impact on Visual Hierarchy and Message Clarity
Sliders can also blur the visual hierarchy of a page. In effective web design, it is essential to guide users toward important information or actions.
However, with multiple slides competing for attention, it becomes difficult for users to discern the main message or the desired action. This confusion can reduce communication effectiveness and hinder the user's ability to make informed decisions on the site.
Sliders and web performance: a major impact
The use of sliders or carousels on websites has a mechanical negative impact on web performance. While they may seem aesthetically pleasing, sliders lead to several technical issues that affect the speed and efficiency of the site. Let's look concretely at how sliders affect the performance of web pages.
Increased DOM volume
Sliders increase the volume of the site's Document Object Model (DOM). Each element of a slider – images, text, buttons – adds extra nodes to the DOM. A large DOM slows down page rendering time, as the browser must process a greater number of elements.
This is all the more problematic because, by definition, a majority of a slider's "screens" are not immediately visible to the user. The increased processing cost is therefore, from a purely practical standpoint, totally unnecessary during initial loading. The more elements present in the slider, the worse the impact will be.
Increased number of downloaded resources
The JavaScript that manages sliders does not always effectively support image lazy-loading. Lazy-loading is a technique that delays the loading of images until they are needed, i.e., when they enter the user's viewport. The absence of effective lazy-loading results in all slider images being downloaded upon initial page load, thus increasing page weight and loading time.
This bulk download of additional resources, mainly images, further strains bandwidth and can be particularly problematic for users with limited or slow internet connections. The impact on performance metrics like LCP and Speed Index is not negligible.
Increased CPU resource consumption
The continuous animations of sliders, which rely on JavaScript code, lead to an increase in CPU resource consumption. This increased CPU consumption affects not only the site's performance but also the user's device performance.
The increased CPU usage due to sliders can negatively impact metrics such as Total Blocking Time (TBT) and Interaction to Next Paint (INP). TBT measures the amount of time the browser's main thread is blocked long enough to prevent user input.
INP measures the delay between a user's interaction with your page and when the browser is able to respond to that interaction. Sliders, by excessively taxing the CPU, can increase these times, thereby degrading the user experience.
Is your site as fast as your visitors expect?
Sliders and eco-design: unnecessary pollution
In the context of the eco-responsible web design that we encourage, the evaluation of sliders must take into account their environmental impact. Web performance aspects, as discussed previously, have a direct repercussion not only on user experience but also on resource consumption and the ecological footprint of websites.
Increased CPU resource consumption
The intensive use of CPU resources by sliders, due to continuous animations and the management of multiple DOM elements, leads to higher energy consumption. This increased energy consumption is not only a burden on users' devices but also contributes to a larger carbon footprint.
In a context where reducing the carbon footprint is essential, this aspect of sliders is particularly concerning.
Excessive bandwidth usage
As mentioned earlier, sliders often increase the number of resources downloaded, especially images. This increase translates into greater bandwidth usage, which is particularly problematic for users with limited or data-costly connections.
Increased bandwidth usage implies a greater demand for data transmission, which increases the energy consumption of data networks and data centers. This rise in energy consumption contributes to the overall carbon footprint associated with Internet browsing.
Sliders: what alternatives for modern and efficient pages?
In the era of contemporary web design, the evolution towards a minimalist and focused approach is increasingly favored. This approach eliminates the complexity and distraction of sliders in favor of clear and direct communication. Adopting static, focused content aligns perfectly with this approach, offering a controlled and intentional user experience.
Static and focused content
Instead of using sliders, consider highlighting static, well-defined content. This choice allows users' attention to be focused on a single, relevant message, without the distractions associated with movement and multiple slides. A high-quality static image, combined with a compelling headline and a clear call-to-action (CTA), can create a strong visual impact while guiding the user toward a specific action.
Benefits of minimalism in web design
Minimalism in web design is not just about a clean aesthetic; it's also an effective strategy for improving web performance. By reducing the number of elements on a page, we decrease the DOM load, optimize loading times, and improve accessibility. This simplicity also allows for better understanding of the message by users, thus promoting more direct and intentional interaction.
What can we conclude?
Replacing sliders with static, focused content is not just a design choice; it's a strategic decision aligned with current trends in web efficiency, accessibility, and sustainability.
This transition towards thoughtful minimalism promotes a clearer and more direct user experience while optimizing the overall performance of the website. For web-focused businesses and startups, adopting this approach represents a significant step towards creating modern, effective, and responsible websites.
