Ultra-thin phones like the Galaxy S25 Edge are quickly heating up. And I'm looking forward to them, but not because of their thinness.

I went hands-on with the world's thinnest phone at MWC 2025, and it was amazing. Tecno's Spark Slim is just 5.75mm thick, but it somehow has a 5200mAh battery.

Samsung has been teasing its super-thin Galaxy S25 Edge since CES in January, and now the company brought a bunch of actual devices to Mobile World Congress (MWC) in Barcelona. There was a catch, though: I wasn't allowed to touch them.

Thinner than the rumored thickness of the Galaxy S25 Edge, the Tecno Spark Slim is a concept phone that's beaten Apple and Samsung to the punch.

Reportedly, Samsung's ultra-thin Galaxy S25 Edge model could be launched next month, while sales are expected to begin in May

Remember when Samsung teased a thinner Galaxy S25 at the Unpacked event last month? It’s happening sooner than we imagined. As the flowers bloom and the bees buzz, Samsung will sprout the Galaxy S25 Edge, which we expect to be its thinnest flagship. The Seoul Economic Daily reports that the Galaxy S25 Edge will have its launch event on April 16.

A hands-on Galaxy S25 Edge video published earlier teased the high-end specs of the ultra-thin phone, teasing amazing performance

As Samsung and Apple battle it out for thin supremacy, it's not surprising that other phone makers are attempting their own version of the "thinnest" phone. Samsung has the Galaxy S25 Edge coming later this Spring, and Apple is expected to launch the iPhone 17 Air in September with the its normal iPhone announcement.

Following its Unpacked unveiling in January, the company showcased the slimmed-down Galaxy S25 model in Barcelona.

There have been several rumours surrounding an iPhone 17 Air over the last couple of months, Oppo announced the world's thinnest folding phone in its Find N5, and Samsung teased the S25 Edge during the launch of its current flagships.