How much can a smartphone really become a smartphone?
If you ask Samsung, it can go up to 6.4 mm – it is how thick its next Galaxy S25 EDGE will be, which makes it the thinnest phone in the 2025 range of the company.
But this is clearly not the limit on phones, and Tecno has proven it. The new spark of the Chinese company is an incredible 5.75 mm, making it the thinnest phone in the world to date.
I had the opportunity to try it at the MWC 2025 in Barcelona, and it is an incredibly impressive engineering feat. We really feel like you have to keep something from the future.
Anyron Copeman / Foundry
However, Tecno wants to emphasize that this is just a concept. The company does not intend to bring Spark Slim to the market, even in its native China.
And it is hardly surprising, because there are two key problems that I can see with this ultra-cliente design.
The first is sustainability – the thin spark does not have the robust feeling that you get thicker and heavier phones, and it seemed a little fragile in my hand. If I accidentally sat on it or dropped it on the sidewalk, I would be worried if it could survive.
Overheating is also a major concern. Tecno supposed to have succeeded in a 5200 mAh battery in the Spark Slim, but that surely leaves no room for an appropriate cooling system.
In its current form, I would be reluctant to use the phone for all demanding tasks, but even use it while the load would look like a risk.
However, none of these questions criticizes Tecno. Even in the form of a concept, the company has shown that an ultra-client apparatus is possible, opening the way to a phone similar to being published in the future.
For his desire to push boundaries, the Tecno Spark Slim deserves a place in the Best of MWC 2025 prices of the technological advisor.
