MWC 2025: Tecno Spark Slim concept claims the title of the world's thinnest smartphone

Tecno’s latest Spark Slim is touted as the “world’s thinnest smartphone.” At just 5.75mm thick, this concept phone is about cutting down the bulk without cutting corners. Despite its ultra-slim frame, Tecno squeezed in a 5200mAh battery, somehow packing all that juice into a 4.04mm design, as per the brand. 

Up front, there’s a 6.78-inch 3D curved AMOLED display with a 144Hz refresh rate, 1.5K resolution, and an eye-searing 4500 nits of peak brightness—because who doesn’t love a screen that shines like a mini sun?

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Tecno says the Spark Slim has a "high-performance octa-core chip" without revealing the details. It sports a 50MP dual-camera setup on the back and a 13MP selfie shooter up front. And, the phone is crafted from recycled aluminium with a stainless steel frame.