This Credit Card-Sized E-Reader Is 15% Off in Amazon’s October Prime Day Sale

Prime Day is usually a great time to score a good deal on a Kindle device, but in the lead-up to Amazon’s “Prime Big Deal Days” event, taking place Oct. 6-7, I would like to redirect your attention to another category of e-readers entirely. Tiny e-ink devices—I’m talking credit card-sized, with screens that measure around 4 inches—are all the rage in 2026, and if you too can see the appeal of carrying all of your books with you on a device so small you’ll forget it’s even in your pocket, it’s not a bad time to jump in: One of the best options on the market, the recently released Xteink X4 Classic, is 15% off ahead of the big sale.

Xteink is a Chinese startup that shook up the e-reading world last year with the launch of the X4, a super bare-bones device that made up for its lack of features and usability with a cheap sub-$70 price point. Since then, a huge online community of fans has formed around the device, sharing tips on Reddit and even coming together to crowdsource an alternate operating system that fixes a lot of its early problems. Xteink quickly followed up the X4 with a slate of other devices, including the even smaller X3 and the X4 Pro, which adds a front light and touchscreen (at the cost of screen clarity and two physical buttons).

The X4 Classic was released earlier this month, replacing the original X4 and adding in some of the quality-of-life improvements that were made with subsequent devices, including a larger battery, relocated page-turn buttons, a real-time clock, USB drive support, and a tilt-to-turn-page feature. The X4 Classic is also 6g lighter and a millimeter thinner than the X4, though there is a trade-off involved there with the latter’s USB-C charging port swapped out for magnetic pogo pins that require a separate cable or adapter.