When you hear "e-reader," you think Amazon Kindle or Kobo. Six-inch screens, weeks of battery life, wireless bookstores. But what if the reader lived on the back of your phone? Credit-card sized, weighing 58 grams, snapping on magnetically?

That is the question Xteink asked.

What Is Xteink?

Xteink is a technology startup founded in China in 2024. The founders' motivation was simple: "What if a reader could be carried in your pocket, just like your phone?" The first product, the Xteink X4, launched internationally in December 2025 and quickly gained attention across the tech world.

The brand's starting point addressed the biggest handicap of traditional e-readers: size. Carrying a Kindle in your pocket is not practical. It needs to go in your bag. Xteink shrank the device down to phone size, or smaller. Magnets embedded in the back allow it to snap directly onto MagSafe-compatible phones. You pull out your phone, flip it over, and start reading.

Three factors drove Xteink's rapid rise to a global readership: affordable pricing, portability, and a powerful community. Devices sell for $69 to $99, half the price of a comparable Kindle. Additionally, Xteink devices are hackable. This attracted the open-source community, which created CrossPoint Reader, an alternative firmware that transformed the devices.

The Product Family: X3, X4 Classic, X4 Pro, and S4

Xteink's lineup currently spans four models, each targeting a different reading experience.

Xteink X3: Ultra Compact

The X3 is the smallest member of the Xteink family. A 3.7-inch E-ink screen, 58 grams, and dimensions of 97.6 x 63.7 mm. Literally the size of a credit card.

Specifications:

• Display: 3.7-inch E-ink, 259 PPI
• Dimensions: 97.6 x 63.7 x 5.1 mm
• Weight: 58 grams
• Processor: ESP32-C3, 128 MB RAM
• Storage: 16 GB microSD (expandable to 256 GB)
• Battery: 650 mAh (10-14 days)
• Connectivity: Wi-Fi 2.4 GHz, Bluetooth, NFC
• Charging: Magnetic pogo-pin (no USB-C)
• Extra: Gyroscope (shake to turn pages)

The X3's standout feature is its gyroscope sensor. You can turn pages by gently shaking the device. When reading one-handed, flipping pages without reaching for buttons is remarkably practical. NFC support also simplifies wireless data transfer.

The X3 has no front light and no touchscreen. You can only read it under external light. This is an intentional design choice: a thinner body, a lighter weight.

Xteink X4 Classic: Daily Reading

The X4 Classic (also known as the X4 V2) is the updated version of the original X4. It launched in September 2026, replacing the original X4.

Specifications:

• Display: 4.3-inch E-ink, 219 PPI
• Dimensions: 111 x 69 x 5.9 mm
• Weight: ~68 grams
• Battery: 920 mAh (up from 650 mAh in the original X4)
• Storage: 16 GB microSD (expandable to 256 GB)
• Charging: Magnetic pogo-pin
• Supported formats: EPUB, TXT, MOBI, PDF, PNG

The X4 Classic's biggest improvement is the larger battery. The original X4's 650 mAh cell was bumped to 920 mAh. The trade-off: USB-C port removed, replaced with magnetic pogo-pin charging. All Xteink devices now charge via this magnetic cable.

Like the X3, the X4 Classic has no front light or touchscreen. It is controlled via physical buttons. Shake-to-turn-page is also supported on the Classic.

Priced at $79, it is the budget-friendly, simplified version of the X4 Pro.

Xteink X4 Pro: The Flagship

The X4 Pro launched in July 2026 and is Xteink's most capable device. It was designed to address the X4's shortcomings: a front light and touchscreen were added.

Specifications:

• Display: 4.3-inch E-ink, 219 PPI
• Dimensions: 111 x 69 x 5.95 mm
• Weight: 72 grams
• Battery: 1100 mAh
• Front light: Yes, adjustable brightness and warm/cool tone
• Touchscreen: Yes (alongside physical buttons)
• Storage: 16 GB microSD (expandable to 256 GB)
• Connectivity: Wi-Fi 2.4 GHz, Bluetooth
• Charging: Magnetic pogo-pin
• Color: Space Black
• Price: $99 (list $109)

The X4 Pro's biggest advantage is its hybrid control. Both touchscreen and physical buttons are available. When selecting books or navigating menus, you use touch. When reading, you turn pages with the side buttons. This combination makes navigation on the small screen significantly easier.

The front light means you can finally read in the dark. Brightness and color temperature are adjustable. On a dimming evening commute or in bed before sleep, the X4 Pro adapts.

Digital Trends awarded the X4 Pro an 8/10 for design and 9/10 for display. The reviewer's main criticisms were the finicky magnetic charging cable and the limited stock software.

The X4 Pro is now available on Amazon, making it easily accessible.

Xteink S4: The Future Model (Not Yet Available)

The S4 is Xteink's boldest move. Instead of the ESP32 microcontroller, it runs Android 11. This means you can sideload apps like Kindle, Kobo, Libby, Moon Reader, and more.

Known specifications (China market, unverified):

• Display: 4.3-inch E-ink
• Operating system: Android 11
• RAM: 2 GB
• Storage: 32 GB
• Battery: 1400 mAh
• Weight: ~95 grams
• Thickness: 6.98 mm
• Front light: Yes, adjustable color temperature
• USB-C: Yes
• Price: ~$50 in China (international ~$70 estimated)

The S4's most striking feature is the switch to Android. This means CrossPoint and other open-source firmware scenes will not apply to the S4. CrossPoint and its forks are ESP32-C3 firmware. The S4's Android-based processor is an entirely different category.

However, Android brings major advantages: real e-book store access, PDF support, CBZ comic reading, and KOReader's Android build. Xteink is positioning the S4 as a device for a broader audience.

The S4's status is currently uncertain. It opened for pre-order in China in April 2026, but shipments were delayed. International release plans are unclear. According to Joshua Lowcock's tracker, Xteink has no current plans to release the S4 internationally, and no FCC filing exists.

CrossPoint Reader: The Power of Community

Understanding why Xteink devices are so popular requires knowing about CrossPoint Reader. Xteink's stock software is basic: a simple file explorer, limited format support (EPUB and TXT), two font sizes, no margin control. The hardware is great, but the software is limited.

CrossPoint Reader is an open-source alternative firmware developed by the community to fill this gap. It has over 6,500 stars on GitHub, is MIT licensed, and completely free.

What CrossPoint offers:

• EPUB 2/3 rendering with embedded styles, image support
• Hyphenation, kerning, chapter navigation, footnotes
• Bookmarks, dictionary lookup (StarDict)
• KOReader progress sync (cross-device)
• Web UI for wireless file transfer
• WebDAV support
• OPDS catalog browser (up to 8 saved servers)
• Calibre wireless connect
• 24 UI languages (including RTL support)
• Custom font loading (from SD card)
• Auto page turn
• Screen orientation control
• Custom themes (Classic, Lyra, RoundedRaff)
• OTA updates (directly from GitHub)

Installing CrossPoint does not require technical knowledge. Connect the device via USB-C, go to crosspointreader.com, click "Flash." The process takes a few minutes. Xteink has explicitly stated that units purchased from their official website are not restricted from running third-party firmware.

The community extends beyond CrossPoint. Several forks have been developed:

• CrossInk: Bionic Reading (bolds word stems to increase reading speed), guide dots, improved fonts, and a modern UI redesign
• papyrix-reader: FB2 and Markdown support, Arabic script support
• crosspoint-reader-cjk: Optimized for Chinese, Japanese, and Korean
• inx: Tabbed navigation with a reimagined interface

This ecosystem transformed Xteink from an ordinary Chinese brand into a global phenomenon. The r/XTEINK community on Reddit has thousands of members. Users write guides, solve problems, and develop third-party tools.

Xteink vs Kindle vs Kobo

Comparing Xteink to traditional e-readers means pitting two different philosophies against each other.

Xteink advantages:

• Accessibility: On the back of your phone, in your pocket, always with you
• Weight: 58-72 grams (Kindle 158-182 grams)
• Price: $69-99 (Kindle $110-160)
• Open software: CrossPoint and forks installable
• No subscriptions: Load your books, read unlimited
• Magnetic phone attachment: MagSafe compatible

Xteink disadvantages:

• Small screen: 3.7-4.3 inches (Kindle/Kobo 6 inches)
• Limited stock software: Basic experience without CrossPoint
• Front light only on X4 Pro (standard on Kindle/Kobo)
• No DRM-protected book support (with stock software)
• Magnetic charging cable (no USB-C on X4 Classic, X4 Pro, or X3)
• No waterproofing

The question to ask when deciding: What will you read for? If you want to catch a few pages during idle moments (waiting for the bus, coffee break, doctor's office), Xteink is perfect. It is so light you will carry it without noticing. If you read for long sessions (vacation, couch at home), a 6-inch Kindle or Kobo is more comfortable.

Practical Use Cases

Public Transit

Snap the X3 onto the back of your phone. When you pull out your phone on the subway, your book is ready on the flip side. Replace the doomscrolling urge with reading. One Ekşi Sözlük user put it: "Since I got the X3, I haven't touched my Kindle. Instead of doomscrolling, I read books."

Night Reading

The X4 Pro's front light is ideal for bedtime reading. Lower the brightness, shift to warm light. Read without disturbing your partner.

Travel

The 58-gram X3 fits in a passport pocket. You can display your boarding pass on the E-ink screen. Even if the battery dies, E-ink displays retain the last image.

Library Management

Transfer books wirelessly via the Xteink app (iOS/Android). Sync across devices with XT-Cloud. Connect to Calibre wirelessly (if CrossPoint is installed).

Final Verdict: A Library in Your Pocket

Xteink entered the e-reader market with an unconventional question and answered it with both hardware and price. A 58-gram E-ink screen, magnetic phone attachment, and open-source community support. A tiny revolution from China against Kindle's 15-year dominance.

The X4 Pro, with its hybrid touch + button controls and front light, is the most balanced option. The X3 is for those who want ultra-lightweight. The X4 Classic is a budget-friendly entry point. The S4 remains uncertain, but the Android transition is a bold move.

If you are someone who loves reading but does not want to carry a separate e-reader, Xteink is made for you. In your pocket, on the back of your phone, barely noticeable. And without realizing it, you will find yourself reading more.

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Sources:

• Xteink official website: xteink.com
• CrossPoint Reader: github.com/crosspoint-reader/crosspoint-reader
• Digital Trends X4 Pro review (September 2026)
• The Verge X4 Pro hands-on (July 2026)
• Android Police (September 2026)
• Notebookcheck (July 2026)
• PocketInk S4 tracker (August 2026)

Image credits: Xteink official website (xteink.com), Notebookcheck