A phone already holds every book you own. Reading on one still means notifications, glare, and a battery that fades by dinner. A dedicated reader solves that, though most readers are too big for a jacket pocket.
Xteink built its answer at credit card scale. Footprint runs 111 by 69 millimeters on the Xteink X4 Pro, at 72 grams. At 5.95 millimeters thin, it slips into a bag pocket or a shirt pocket and stays there.
Price: $99
Where to buy: Amazon
One hand runs the whole device, per the maker’s sizing notes. Grip stays comfortable during a long chapter, and page turns need no second hand. Commuters holding a rail with the other hand are the target buyer here.
Size is the whole pitch, and size drives every trade here. A 4.3-inch screen will not suit long PDF sessions or comics. For plain text on a train or in a waiting room, small is the point.
Built-in magnets sit in the back panel. X4 Pro snaps onto compatible phones, so it rides with the device you already carry. Two adhesive metal rings come in the box for phones without magnets.
Carry decides whether a reader gets used. A reader left at home helps nobody, and a reader this light avoids that failure. It adds less weight than a wallet and takes less room than a phone.
A front light changes the brief
Earlier pocket readers from the brand skipped a front light. Reading after dark meant a lamp or nothing. X4 Pro adds an adjustable front light, and that single change widens where it works.
Brightness and light tone both adjust on the device. A warmer setting suits a bedroom, and a cooler setting suits daylight. Readers set it once per spot and get back to the page.
Touch joins physical buttons on this model. Pages turn with a tap, a swipe, or a button press. Readers who want one-handed page turns on a crowded train get both options.
Paper specs, pocket limits
E Ink does the heavy lifting for comfort. A 219 PPI panel keeps text sharp at this size, and the matte surface cuts reflections outdoors. Output stays black and white, as E Ink does.
Storage starts with a 16 GB microSD card in the box. Expansion runs to 256 GB, which holds far more text than anyone will finish. Books load through the Xteink app over Wi-Fi or by USB from a computer.
Setup pairs the reader with the app by QR code. A scan binds the device, then the app sends books, fonts, and wallpapers. Cloud Sync on the reader pulls each file down over Wi-Fi.
USB works as the second route. A menu switch puts X4 Pro into USB mode, and it mounts on a computer like a drive. Files copy across directly, with no account step in the way.
Format support is narrow, and buyers should check it first. Per the maker’s spec block, documents run EPUB and TXT only. Images run JPG and BMP, and fonts load in XTF and BIN formats.
DRM-locked store purchases will not open here. Anyone with a large locked library should look at a store-tied reader instead. Anyone holding EPUB files already owns the right library for this one.
Custom fonts and wallpapers add a personal layer. Both load through the app or by USB, in the formats above. Firmware ships in English, Japanese, and Simplified and Traditional Chinese, with more languages rolling out by update.
Battery and the pogo pin trade
A 1,100 mAh battery sits inside the thin body. E Ink sips power compared with a phone screen, so charging stays an occasional job.
Charging runs through a pogo pin port, not USB-C. A magnetic charging adapter comes in the box, and no charging cable is included. Lose that adapter and you will need a replacement from the maker.
Bluetooth and 2.4 GHz Wi-Fi cover transfers and app sync. A quick start guide, a matte screen protector, and the microSD card round out the box. A one-year warranty and 30-day returns back the purchase.
One warranty line deserves a read before tinkering. Damage from unofficial firmware or third-party modifications sits outside coverage, per the maker’s terms. Paid repair may still be offered, though stock firmware keeps the warranty clean.
Buying one and the verdict
Space Black and Mist Gray both list at $99 on the maker’s store. Stock shows as available, with shipping in one to five days. Amazon carries Space Black at the same $99.
Price puts it in impulse territory for reading gear. A larger reader costs more and travels less, while a phone costs nothing extra and distracts constantly. X4 Pro sits between those poles and charges $99 for focus.
Price: $99
Where to buy: Amazon
Order one if your books live as EPUB files and your reading happens in spare minutes. Skip it if you buy inside a locked store or read PDFs daily. At $99, this reader justifies its pocket space by being present, charged, and light enough to forget until a queue forms.
