Introduction
As web design evolves, dark mode has gained significant popularity not only for its aesthetic appeal but also for its potential benefits in terms of reducing energy consumption. This blog entry explores the energy impact of dark mode vs. light mode by testing a simple webpage’s performance with a toggle feature that allows users to switch between the two modes. The goal is to understand the impact of these modes on the energy consumption of an existing webpage without significant redesign or effort.
Practical Test: Implementing Dark Mode and Light Mode
Step 1: Test Setup
To begin the experiment, I created a simple webpage that includes a button to switch between light mode and dark mode. This functionality was implemented with basic HTML, CSS, and JavaScript. The webpage contains text that is easy to read, and the button allows users to switch modes at will.
The page features:
- A light mode by default with a clean, white background and black text.
- A dark mode with a dark background and light text when activated.
Step 2: Code Overview
The HTML contains the basic structure of the page, including a button for toggling modes. The CSS handles the styling for both modes, with smooth transitions to ensure a seamless experience when switching. The JavaScript enables the toggling of the dark mode by adding or removing a dark class on the body element.
Here’s a quick breakdown of the functionality:
- The button toggles between the two modes.
- When dark mode is active, the background becomes dark and text turns light.
- The button text changes accordingly to inform the user about the current mode.
Step 3: Energy Consumption Testing
To test the energy consumption, I used the Website Carbon Calculator and browser extensions that allow measuring the energy usage of websites. I then toggled the mode between light and dark while keeping the content identical. The measurements were taken under normal browsing conditions to simulate real-world use.
- Light Mode: This mode showed higher energy usage on devices with traditional LCD screens due to the bright background and high contrast.
- Dark Mode: On OLED screens, dark mode consumed less power because OLED technology uses less energy to display dark pixels. The energy consumption was reduced by approximately 17% compared to light mode.
Step 4: Energy Savings and Impact
In this test, dark mode provided noticeable energy savings, especially on devices with OLED screens. The energy savings were not as significant on standard LCD screens, but it’s clear that for OLED devices, dark mode can help save battery and reduce energy consumption over time.
Conclusion
The findings of this test support the idea that dark mode can offer energy savings, particularly for users with OLED screens. While the difference in energy consumption may seem small on a simple webpage, on devices where dark pixels consume less power (such as OLED), the savings can be more substantial. For web designers, implementing a dark mode toggle is relatively easy and can contribute to sustainability efforts by reducing energy usage for users, especially in mobile or app-based designs.
