(Credit: Eric Zeman)
BARCELONA—Budget device maker Tecno showed off a range of new hardware at Mobile World Congress, but none was as impressive as the Spark Slim. This full-featured Android smartphone measures a seemingly impossible 5.75mm (0.22 inches) thick while still packing a battery bigger than the Samsung Galaxy S25 Ultra.
(Credit: Eric Zeman)It's hard to describe just how thin 5.75mm is. The average iPhone 16 measures 7.9mm (0.31 inches) thick, and the Galaxy S25 measures 7.2mm (0.28 inches) thick. Look at your phone and imagine it being 40% thinner. Thin phones typically have lower-capacity batteries due to the limited internal space but Tecno found a battery thin enough to cram into the chassis.
(Credit: Eric Zeman)Other than its dimensions, Tecno isn't saying much about the Spark Slim. It has a large screen, two rear cameras, and all the other design elements of a modern smartphone. Tecno didn't share any specs, such as which processor might be inside, the camera's resolution, and the type of connectivity it might offer. The biggest question is one of performance. The 5.75mm thickness doesn't leave much room for cooling mechanisms like vapor chambers or conductive layers. It's possible a phone this thin could easily overheat.
Recommended by Our Editors
While the phone is impressive, it's unclear if Tecno will pursue manufacturing it. In its note to the press, Tecno said the engineering involved in making the phone is "set to lead the way in the next wave of ultra-thin smartphone design."
We can only hope.