The Mobile World Congress (MWC) 2025 is set to kick off next week in Barcelona, and ahead of the event, Tecno has already made waves by teasing what it claims to be the world’s slimmest smartphone. Named the Tecno SPARK Slim, this ultra-thin device measures just 5.75mm in thickness yet astonishingly packs a 5,200mAh battery—larger than the one in Samsung’s Galaxy S25 Ultra.
With Apple, Samsung, and OPPO all working on slimmer devices, Tecno’s announcement puts it at the forefront of the thin smartphone revolution, at least for now. But will it maintain its title for long?
🔹 The Ultra-Thin Smartphone Race is Heating Up
For months, rumors have circulated about Apple’s iPhone 17 Air, which is expected to measure just 5.5mm thick, potentially dethroning Tecno’s SPARK Slim as the world’s slimmest smartphone. Meanwhile, Samsung has already teased its Galaxy S25 Edge, another sleek device set to launch later this year.
With a growing demand for slim yet powerful devices, it’s clear that 2025 will be a landmark year for ultra-thin smartphones.
🔹 Tecno SPARK Slim: What We Know So Far
📱 5.75mm Thin with a Revolutionary Battery
Tecno’s SPARK Slim pushes the limits of engineering, offering a 5,200mAh battery in an incredibly thin 5.75mm chassis. This hints at the use of silicon carbon battery technology, a new innovation that allows manufacturers to pack larger battery capacities without increasing bulk.
This battery breakthrough is already being used by brands like OnePlus, iQOO, and Poco, with many devices now featuring 6,000mAh+ batteries while maintaining a sleek form factor.
📺 6.78-inch 3D Curved AMOLED Display
The SPARK Slim will feature a stunning 6.78-inch AMOLED panel with a 3D curved design. While Tecno hasn’t confirmed the refresh rate, previous leaks suggest that it will feature a high refresh rate, likely 144Hz, ensuring smooth scrolling and gaming.
📷 Dual 50MP Cameras
In the camera department, Tecno has confirmed that the SPARK Slim will include a dual 50MP camera setup. While details about the sensor size and software processing remain unknown, Tecno’s past devices have delivered competitive imaging capabilities in the mid-range segment.
🔹 Will Tecno’s SPARK Slim Hold the Title for Long?
While Tecno is currently in the spotlight, the battle for the world’s thinnest smartphone is far from over. If Apple’s iPhone 17 Air does launch with its rumored 5.5mm thickness, it could easily steal the crown from Tecno. However, it remains to be seen whether Apple can match Tecno’s massive 5,200mAh battery capacity in such a slim form factor.
Meanwhile, Samsung’s Galaxy S25 Edge is expected to offer a balance between slimness and performance, though the company hasn’t confirmed its exact dimensions yet.
Bhupendra Singh Chundawat is a seasoned technology journalist with over 22 years of experience in the media industry. He specializes in covering the global technology landscape, with a deep focus on manufacturing trends and the geopolitical impact on tech companies. Currently serving as the Editor at Udaipur Kiran, his insights are shaped by decades of hands-on reporting and editorial leadership in the fast-evolving world of technology.
