Open a model or jump to the table. The Xteink X3 and the X4 Pro ship now. The original X4 is discontinued. The S4 is China-only, per our S4 guide.
The upgrade pick. Front light and touchscreen for $99.
The X4 with a warm/cool front light and a touchscreen, side buttons kept. 72 g, 1,100 mAh battery, pogo-pin charging instead of USB-C. Runs XTOS, not Android. The Android model is the S4, even though this used to be called V2 Pro.
The smallest one. 58 g, snaps to the back of your phone.
58 g, 3.7-inch E Ink. Snaps to the back of your phone with magnets, and charges over pogo-pin, not USB-C.
The usual first Xteink. 4.3", USB-C, $69.
Discontinued. The 4.3-inch USB-C Xteink, $69, and the centre of the firmware scene. Magnetic-ready. No front light or touchscreen.
Size check
The smallest e-reader in this comparison is the Xteink X3: a 3.7-inch E Ink reader that measures 97.6 × 63.7 × 5.1 mm and weighs 58 g.
| Lightest first | Weight | Thickness | Screen | In a line |
|---|---|---|---|---|
| Xteink X3 | 58 g | 5.1 mm | 3.7" | The smallest; snaps to a phone back |
| Xteink X4 Pro | 72 g | 5.95 mm | 4.3" | Lightest with a front light |
| Xteink X4 | 77 g | 5.9 mm | 4.3" | Discontinued; last official price $69 |
Spec table
The live split is X3 vs X4 Pro. The original X4 is discontinued. Specs below, or build your own pair.
| Spec | X3 | X4 discontinued | S4 soon | X4 Pro |
|---|---|---|---|---|
| Colours | Space Black Mist Gray | Space Black Mist Gray | Not disclosed | Space Black White
?
|
| OS / platform | Proprietary firmware * | Proprietary firmware * | Android 11 * | XTOS (non-Android) |
| Screen | 3.7" E Ink | 4.3" E Ink | 4.3" E Ink * | 4.3" E Ink, 219 PPI |
| Resolution | 259 PPI | 220 PPI | Not disclosed ? | 219 PPI |
| Front light | No | No | Yes (adjustable temp) * | Yes, adjustable brightness + warm/cool |
| Touchscreen | No | No | Not disclosed ? | Yes + side page-turn buttons |
| Chip | ESP32-based * | ESP32 | Not disclosed ? | Not disclosed ? |
| Storage | 16 GB microSD, exp. 256 GB | 16 GB microSD, exp. 256 GB | 32 GB + microSD · 2 GB RAM * | 16 GB microSD, exp. 256 GB |
| Charging | Magnetic pogo-pin | USB-C | USB-C * | Magnetic pogo-pin |
| Battery | 650 mAh | 650 mAh | 1,400 mAh * | 1,100 mAh |
| Dimensions | 97.6 × 63.7 × 5.1 mm | 114 × 69 × 5.9 mm | Not disclosed ? | 111 × 69 × 5.95 mm |
| Weight | 58 g | 77 g | 95 g * | 72 g |
| Thickness | 5.1 mm | 5.9 mm | 6.98 mm * | 5.95 mm |
| Magnetic mount | Yes | Yes | Yes (to phone) * | Yes, built-in magnetic backplate |
| Price | $69 | $69 | CNY 339 (~$50) · China-only * | $99 |
Default pick. If you just want a pocket reader, start with the $69 Xteink X3. The original X4 is discontinued.
Buy the Xteink X3Beyond Xteink
Yes. The Obook5 Mini is a 4.26-inch reader with a front light and an audiobook speaker, $109.99 on Amazon. Compared here to the discontinued Xteink X4.
| Spec | Xteink X4 | Obook5 Mini |
|---|---|---|
| Screen | 4.3" E Ink, 220 PPI | 4.26" E Ink, 219 PPI, 4-level grayscale |
| Front light | No | Yes, adjustable |
| Battery | 650 mAh | 1,200 mAh |
| Weight | 77 g | 94 g |
| Storage | 16 GB microSD, exp. 256 GB | 32 GB |
| Price | $69 | $109.99 |
China only
No. China-only as of August 2026, per Joshua Lowcock's S4 tracker. Importing is the only route. Full story in our S4 guide.
The Android model. Sideload Kindle, Kobo, anything.
Xteink's first Android model. Sideload Kindle, Kobo, or any reading app, plus Xteink's first front light. Sold in China only. Joshua Lowcock's tracker shows no international release planned as of August 2026, so importing is the only route.
Questions
Sources: the-ebook-reader.com
Sources: the-ebook-reader.com (Obook5 price)
Sources: TechCrunch X3 review