Xteink Updates X4 E-Reader: What the Bluetooth and Font Fixes Mean

Xteink has released a system update for its X4 e-reader that fixes Bluetooth connectivity problems and adds support for more languages. The update improves how the device connects to smartphones, prevents freezing during wireless use, and adds 1,841 new characters to the built-in font library. It also makes image display smoother.

The X4 is a slim, lightweight device weighing 74 grams with a 4.9mm profile, priced at $69. It's designed for people who prioritize portability over screen size. Like many smaller tech companies in the e-reader space, Xteink uses a proprietary app ecosystem — meaning you can only access content through their own software rather than via open standards. This limits third-party compatibility but allows the company to optimize the hardware and software to work tightly together.

Fixing Bluetooth Reliability

The original X4 had real problems with Bluetooth connectivity. The update targets the underlying wireless code that manages how the device pairs with and stays connected to phones.

E-ink devices face a familiar engineering constraint: Bluetooth drains battery quickly. The X4 promises 14 days of battery life from a small 650mAh cell (tiny by smartphone standards). To achieve that, manufacturers must cut power consumption aggressively — but cut too much and wireless connections fail or the device freezes during data transfer. The update suggests the first version of the X4 was too aggressive on the power-saving side.

The improvements allow the device to scan for Bluetooth devices faster and hold a stable connection without requiring a reset. For an e-reader that syncs content wirelessly, this is essential.

Expanding Language Support

The 1,841 new characters added to the built-in font suggest Xteink is targeting international markets, likely adding support for languages like Chinese, Japanese, Korean, or Arabic that require many more characters than English. Rather than load these fonts from the internet each time (which would slow the device down), Xteink has embedded them directly into the device's firmware.

This differs from how Amazon's Kindle handles languages — Kindle relies on cloud-based rendering and larger storage to support many languages at once. Xteink's approach is faster and works offline, but it means you're limited to the character sets the company has decided to include. You can't easily add custom fonts the way you might on a Kindle.

Improving Image Display

E-ink screens are clever but finicky. To display an image on an e-ink display, the device must go through a series of refresh cycles — essentially pulsing the screen to transition pixels from white to black through intermediate gray tones. If this process isn't done carefully, images can look smudged or ghostly, particularly problematic when reading PDFs with charts, diagrams, or comics that mix text and images.

The update improves how the X4 processes and displays JPG images by using better buffering or smarter algorithms to convert color images into the black-and-white format the screen can show. This makes technical documents and graphics easier to read.

The Bigger Picture

The X4 competes directly with Amazon's cheapest Kindle models, undercutting them by $20–30. Its tiny size and magnetic backing are designed for specific use cases — mounting on a car dashboard, attaching to exercise equipment, or fitting into a travel bag where every gram matters. It's not a full-featured e-reader replacement but rather a specialized tool for people with particular needs.

The reliance on proprietary software is worth examining. Smaller hardware makers often lock users into their own apps because they can't match the resources of companies like Amazon or Kobo. This gives them tighter control over the hardware-software relationship but frustrates users who want more choice. We have seen this pattern before during the early smartphone era, when companies like HTC and Motorola created custom Android versions to stand out from the crowd. Some delivered genuine value; others just locked people in without good reason.

Xteink's real test will be whether their proprietary approach actually gives users features they can't get elsewhere — or whether it simply forces them to use clunky software. The regular firmware updates are a good sign the company intends to support the device long-term, but the scale of the Bluetooth issues in the initial release does raise questions about how thoroughly the X4 was tested before launch.

The e-reader market has largely consolidated around Amazon's dominance. Xteink's bet on extreme portability and proprietary optimization represents one more attempt by a smaller player to find a defensible niche. Whether that niche is large enough to sustain the business is unclear — but this first system update shows the company is listening to early users and willing to invest in fixes.