Amid rumors about a thinner iPhone, Tecno has unveiled a phone concept, called the Spark Slim, that's skinnier than a pencil. I got to hold it at Mobile World Congress in Barcelona, and it's certainly the lightest and thinnest phone I've ever encountered (the company says it's just 146 grams).

At MWC 2025, Tecno unveiled its Spark Slim smartphone. While the company calls it a concept device (read: prototype), it is reportedly preparing for a "staggered launch" later this year. Regardless, after brief hands-on time with the phone, I can confidently say this is how thin phones should be done.

The Tecno Spark Slim is an ultra-thin, high-end Android phone that looks a lot like the rumored iPhone 17 Air - here's what it has to offer.

Ahead of MWC, Tecno teased the Spark Slim as the “industry’s slimmest phone.” The 5.75mm device won’t break records, as the mostly-forgotten Moto Z was much thinner at just 5.2mm, but it does something that the Moto Z,