WTF?! Conventional wisdom suggests that using dark mode on apps and websites helps conserve battery life on your devices. However, new research is challenging this belief, suggesting that dark mode may actually drain energy for most users.
The surprising findings come from the BBC's R&D team, who examined how real users interact with their devices in both dark and light modes. Participants were asked to sit in front of the BBC Sounds homepage and adjust the device brightness to a comfortable level. This process was repeated for both the light and dark mode versions of the page.
A significant majority (80 percent) of participants increased their screen brightness much higher to improve visibility in dark mode. This created a "rebound effect," leading to much higher energy consumption compared to the supposedly more wasteful light mode.
Zak Datson, a BBC R&D engineer, explained that many common sustainability tips are overly simplified and fail to consider how people actually use technology in real-world scenarios.
The findings were published in the journal Joule and are part of an ongoing BBC R&D project exploring the effectiveness of typical guidelines for creating low-energy websites and apps.
"What we need is a better understanding of what exactly causes our devices to consume energy when we spend time online," Datson said. "That's what our team is working on, so that we can make changes based on evidence that will allow us to reduce the overall footprint of digital media consumption, both here at the BBC and for the wider media industry."
Too often, the BBC team found that energy advice for developers lacks solid data to back it up. As a result, coders end up wasting effort on changes that don't truly improve sustainability. The research also examined whether making websites more responsive translated to energy efficiency gains and found that it did not.
So, if dark mode isn't the battery-saving hack it was thought to be, what should actually be done to conserve energy? The most straightforward solution is simply dimming the screen brightness. BBC's research shows that using devices at maximum brightness can double power consumption. They also recommended opting for smaller screens, such as phones and tablets, which use less energy than laptops. Another practical tip is extending the lifespan of aging devices, as each new device produced has significant environmental costs.
To be fair, the team doesn't completely dismiss dark mode's merits. Their blog acknowledges that research has shown that for certain devices, adopting darker color schemes can legitimately reduce power usage. However, this is true only under controlled conditions. The researchers' main point is that these numbers haven't been tested in real-world scenarios, where user behavior can lead to unexpected outcomes.
Masthead credit: Walling
Dark mode could drain more battery than light mode, BBC study says
