World’s Thinnest Smartphone Unveiled: Tecno Spark Slim at 5.75mm, Thinner Than a Pencil
Tecno Spark Slim: World’s Thinnest Smartphone Debuts at MWC 2025
At Mobile World Congress (MWC) 2025 in Barcelona, Tecno Mobile unveiled the Tecno Spark Slim—a concept smartphone measuring just 5.75mm thick, slimmer than a standard pencil (6mm) and even Samsung’s Galaxy Edge (5.84mm). MailOnline got hands-on with the device, crafted from recycled aluminum and stainless steel, which boasts a mirror-like finish and a surprisingly hefty 5,200mAh battery for its ultra-slim frame.
The Tecno Spark Slim (5.75mm) compared to a pencil.
Key Specs and Design
The Spark Slim features a 6.78-inch display and Tecno’s “unstoppable power” tagline, highlighting its balance of thinness and functionality. While still a concept (not slated for imminent release), the device is fully functional, unlike dummy prototypes. Its stainless steel unibody and eco-friendly materials aim to merge futuristic design with sustainability.
Slimmer Than the Competition
Samsung’s Galaxy Edge, launching later in 2025, trails slightly at 5.84mm. At MWC, Samsung’s booth guarded the Edge closely, suspending it behind wires—MailOnline was shooed away by security during a closer inspection. Meanwhile, Tecno’s Spark drew crowds, its sleek profile showcasing the industry’s race for extreme thinness.
Samsung’s Galaxy Edge (5.84mm) hung under tight security at MWC.
Ultra-Thin Trend Heats Up
Smartphone makers are prioritizing slimmer builds for portability and style. Apple is rumored to join the trend with an “iPhone 17 Air” later this year. While thinness aids discreet portability, Tecno’s large battery defies expectations—surpassing even the Samsung S25 Ultra’s 5,000mAh capacity.
MWC 2025 Highlights
Beyond the Spark Slim, MWC showcased quirky tech, including Realme’s temperature-sensitive phone (changes color in the cold) and Lenovo’s AI-powered ThinkBook “Flip” PC with a proportionally massive screen. Over 100,000 attendees explored innovations from giants like Huawei, Xiaomi, and Microsoft.
Crowds gather around Tecno’s futuristic concept device.
What is MWC?
Mobile World Congress, held annually in Barcelona, is the premier event for mobile tech. This year’s theme, “Converge. Connect. Create,” emphasized network advancements alongside hardware. While Apple skips MWC for solo launches, rivals like Samsung and Tecno dominate the spotlight with boundary-pushing designs.
The Spark Slim’s 6.78-inch display and robust battery packed into a razor-thin body.
Tecno’s Spark Slim exemplifies the industry’s thinness obsession, blending aesthetics with surprising power. Though still conceptual, it signals a future where smartphones prioritize form without sacrificing function.
