How thin can a smartphone really become?
If you ask Samsung, it can go as low as 6.4 mm – the upcoming Galaxy S25 Edge will be as thick, making it the slimest phone in the Line -Up of 2025 of the company.
But that is clearly not the limit as far as telephones can go, and Tecno has proven it. The new Spark Slim from the Chinese company is an incredible 5.75 mm, making it the thinnest phone in the world so far.
I had the chance to try it on MWC 2025 in Barcelona, and it is an incredibly impressive performance of Engineering. It really feels like you are holding something from the future.
Anyron Copeman / Foundry
However, Tecno wants to emphasize that this is just a concept. The company is not going to market the Spark smartly, even in his native China.
And it is not surprising, because there are two important problems that I can see with this ultra-slim design.
The first is durability – the Spark Slim does not have the sturdy feeling that you get from thicker and heavier phones, and it felt a bit thin in my hand. If I accidentally sat on it or dropped on the sidewalk, I would be worried if it could survive.
Overheating is also a great concern. Tecno was probably managed to smartly squeeze a 5200 mAh battery in the Spark, but that certainly leaves no room for a good cooling system.
In his current form, I would be reluctant to use the phone for demanding tasks, but even use during charging would feel a risk.
However, none of these issues is a criticism of Tecno. Even in concept form, the company has shown that an ultra-slim device is possible, so that the road is cleared for a similar phone in the future.
For his desire to push the boundaries, the Tecno Spark Slim deserves a place in the best of MWC 2025 Awards from Tech Advisor.
