
E-readers are secondary devices. You know… the kind you’ll pack in the luggage when you’re traveling, but you’re likely to leave at home on a normal weekday. You already have a phone that will let you read books, after all, so carrying a single-purpose device that’s bigger than your phone just doesn’t make sense. But what if you made the e-reader smaller than a modern smartphone? That’s the idea behind the Xteink X4.
That’s right, there’s another small e-reader in town and it’s even more compact than the Boox Palma series. It’s so small, in fact, you can snap it to the back of an iPhone using its MagSafe connector, making it pretty convenient to carry for a second device.

The Xteink X4 might be the smallest production e-reader today, coming with just a 4.3-inch E-Ink screen, so it looks a lot like the early smartphones from the late 2000s. The screen is only grayscale, so no color, with a 220 PPI pixel density, which should be sharp enough for most reading needs, although it is quite low compared to the 300+ PPI screens on most modern e-readers. It’s slim, too, with a housing that measures just 5.9mm (0.2 inches) thick, so it should comfortably fit in any pants pocket. The whole thing fits easily in the palm of the hand, as well, so you can literally bust this out and continue reading a book anywhere you are.
It comes with physical page turn buttons underneath the screen, making it easy to flip through books and scroll through documents. Do note, there’s no touchscreen support, so you’re stuck using the buttons for interacting with the device. There’s also a physical power button, so you can turn it on and off at will. The device measures 4.5 x2.7 x 0.2 inches (height x width x thickness) and weighs 2.6 ounces (74 grams), so taking this with you everyday should be no problem.

The Xteink X4 comes with magnets in the back that allow it to snap onto MagSafe-compatible phones. Sadly, they designed it with older iPhone models in mind, so it might not align perfectly with newer devices. If that’s the case, the outfit included magnetic adhesive rings in the package, so you can still snap it onto newer iPhones and Android smartphones. You just need to find the proper alignment. It also comes with a folio-style case like many modern e-readers if you want to carry it on its own.

Inside, it’s powered by an ESP32 CPU with 128MB of RAM, Wi-Fi, and Bluetooth. There’s also an SD card slot with a 32GB card preloaded, although it supports any memory card up to 512GB. It’s fitted with a 650 mAh battery, which is rated to last for two weeks under moderate use. It runs a custom OS that’s strictly for reading books. That’s right, there’s no third-party app support or any built-in extraneous apps. It also has limited file format support, only working with epub, txt, jpg, and bmp, so it’s a really barebones device, which shouldn’t be an issue considering how affordable it is.
Speaking of affordability, the Xteink X4 is available now, priced at just $69.