Seoul Lowers Brightness of 8 in 10 Outdoor Digital Billboards
- Yul So
- Apr 20
- 2 min read
Apr 20, 2026
Yul So
Seoul has reduced the brightness of most large outdoor digital billboards as part of a citywide effort to save energy and reduce light pollution. According to the Seoul Metropolitan Government, about 79 percent of inspected billboards have already adopted the new brightness guidelines.
The city reviewed 200 outdoor screens larger than 30 square meters. Among them, 158 sites had lowered brightness levels or introduced automatic control systems. A total of 109 billboards installed automatic brightness adjustment devices, and 105 of them are currently in operation. These systems automatically change screen brightness based on surrounding light conditions. This helps reduce unnecessary electricity use while keeping displays visible during the day and night.
City officials estimate that the new measures could save about 17,255 megawatt hours of electricity during the day and 15,249 megawatt hours at night each year. Combined, that amount of energy is enough to power around 9,000 households for one year. Lower brightness levels are also expected to reduce glare for pedestrians and drivers, improving the urban environment. In March, Seoul became the first city in Korea to introduce a daytime brightness guideline for outdoor digital displays, setting a limit of 7,000 candelas per square meter. Nighttime rules were also divided by screen size and operating hours and took effect in April.
Additional steps have been introduced in busy commercial areas such as Gwanghwamun and Myeongdong, where some billboards are also shortening operating hours. Seoul officials said they plan to expand inspections beyond designated media districts and continue monitoring billboard brightness across the city. They added that the policy is designed to improve public comfort while supporting energy conservation goals.
