Onyx Boox Note Air 4 C

Name: Onyx Boox Note Air 4 C
Brand: Onyx
SKU: 15408

Manufacturer: Onyx

The Onyx Boox Note Air 4 C is a 10.3-inch e-reader from Boox designed for reading, note-taking, and document handling. Weighing 430 g with a slim 5.8 mm profile, it runs on an open-source Android-based platform that supports a wide range of apps and customization options. Its color e-paper display is self-lit and features an anti-reflection coating, making it usable across varied lighting conditions without the harshness of a conventional backlit screen.

Under the hood, the device is equipped with 6 GB of RAM, 64 GB of internal storage, and a CPU running at 8 cores at 2 GHz each, with support for up to 2 TB of additional external memory. Connectivity includes Wi-Fi 5 (802.11ac) and Bluetooth 5.1, while the 3,700 mAh rechargeable battery charges via USB Type-C. The Note Air 4 C also supports 26 file formats, text-to-speech, stereo speakers, on-device machine learning, split-screen multitasking, and offline voice recognition, rounding out a broad feature set for an e-paper device.

Pros

The 10.3-inch e-paper display delivers a pixel density of 300 ppi at 1860 x 2480 px resolution, producing sharp text and detailed rendering suitable for reading and note-taking
The self-lit screen combined with an anti-reflection coating makes the display usable across a wide range of lighting environments without glare
With 64 GB of internal storage and an external memory slot supporting up to 2000 GB, there is substantial room for large document and media libraries
The 8-core CPU at 2 GHz paired with 6 GB of RAM provides a capable foundation for multitasking, split-screen use, and running multiple apps
At just 5.8 mm thick, the slim profile makes the device relatively easy to handle during extended reading or writing sessions
The platform is free and open source, and supports 26 file formats along with offline voice recognition, text-to-speech, and on-device machine learning

Cons

At 430 g, the device is on the heavier side for an e-reader, which may cause fatigue during prolonged one-handed use
The battery does not support fast charging or wireless charging, meaning recharging relies solely on a wired USB Type-C connection at standard speeds
There is no 3.5 mm headset jack, limiting wired audio options for users who prefer headphones
The display does not include branded damage-resistant glass, offering less protection against physical impact or scratching
No cellular connectivity is available, restricting internet access to Wi-Fi only

Who is this for?

This device is well suited to avid readers, students, and professionals who need a capable e-reader for handling large volumes of documents, PDFs, and diverse file formats. With support for 26 file types and up to 2000 GB of expandable storage, it accommodates users who maintain extensive libraries. The open-source platform, split-screen multitasking, and on-device machine learning also make it a solid fit for note-taking and annotation workflows, while the self-lit 300 ppi e-paper display is particularly well suited to those who read for extended periods and want a screen that is easy on the eyes across varied lighting conditions.

Who is this NOT for?

Users looking for a lightweight, easy-to-hold device for casual one-handed reading may find the 430 g weight uncomfortable over long sessions. Those who rely on mobile data for connectivity will be limited by the absence of a cellular module, making this a poor fit for users who need internet access away from Wi-Fi. Additionally, anyone seeking a device for media consumption through wired headphones will be hindered by the lack of a 3.5 mm audio jack, and users who frequently need quick recharging will find the absence of fast charging and wireless charging inconvenient.

Design:

weight	430 g
volume	252.9844 cm³
width	193 mm
thickness	5.8 mm
height	226 mm

The Onyx Boox Note Air 4 C has a height of 226 mm and a width of 193 mm, giving it a footprint suited to a full-size e-reader experience. At just 5.8 mm thick, the device maintains a notably slim profile, while its weight of 430 g and total volume of 252.98 cm³ reflect a build that balances screen size with physical presence.

Display:

screen size	10.3"
is self-lit	✓
pixel density	300 ppi
Has an e-paper display	✓
has a touch screen	✓
has anti-reflection coating	✓
resolution	1860 x 2480 px
has branded damage-resistant glass	✕

The device features a 10.3″ e-paper touch screen with a resolution of 1860 x 2480 px and a pixel density of 300 ppi, delivering sharp, detailed rendering across text and graphics. It is self-lit and includes an anti-reflection coating, reducing glare for more comfortable viewing in various lighting conditions. The display does not incorporate branded damage-resistant glass.

Performance:

internal storage	64GB
has an external memory slot	✓
RAM	6GB
CPU speed	8 x 2 GHz
maximum amount of external memory supported	2000GB

The device is powered by an 8-core CPU running at 2 GHz per core and comes paired with 6 GB of RAM, providing a capable foundation for handling documents, apps, and multitasking. It includes 64 GB of internal storage and an external memory slot that supports expansion up to 2000 GB, offering considerable flexibility for users with large media or document libraries.

Connectivity:

has a cellular module	✕
supports Wi-Fi	✓
Wi-Fi version	Wi-Fi 4 (802.11n), Wi-Fi 5 (802.11ac)
Has Bluetooth	✓
Bluetooth version	5.1
has a search browser	✓
has NFC	✕
has an HDMI output	✕

Wireless connectivity is handled through Wi-Fi 4 (802.11n) and Wi-Fi 5 (802.11ac), alongside Bluetooth 5.1 for peripheral and device pairing. A built-in browser is also included for web access. The device does not support cellular connectivity, NFC, or HDMI output.

Battery:

battery power	3700 mAh
Has USB Type-C	✓
has a removable battery	✕
Supports fast charging	✕
has wireless charging	✕
has a rechargeable battery	✓
has a battery level indicator	✓

The device is equipped with a 3700 mAh rechargeable battery that charges via USB Type-C, and it includes a battery level indicator to keep track of remaining charge. The battery is non-removable, and the device does not support fast charging or wireless charging.

Features:

has a built-in speaker	✓
has dictionary	✓
supported file types	26
supports text-to-speech	✓
has a socket for a 3.5 mm audio jack	✕
has GPS	✕
has stereo speakers	✓
has an accelerometer	✓
has a compass	✕
Has a radio	✕
has a front camera	✕
has a built-in HDR mode	✓
has a child lock	✕
has a gyroscope	✓

On the audio side, the device includes stereo speakers with text-to-speech support, though it lacks a 3.5 mm headset jack. A built-in dictionary is available alongside support for 26 file types, making it versatile for reading across a range of document formats. The display features a built-in HDR mode, and motion sensing is handled by both an accelerometer and a gyroscope. The device does not include GPS, a compass, a radio, a front camera, or a child lock.

Miscellaneous:

has media picker	✓
has notification permissions	✓
has Mail Privacy Protection	✕
Tracks the current position of a mobile device	✓
blocks cross-site tracking	✕
can block app tracking	✓
has Quick Start	✕
has dynamic theming	✓
is a multi-user system	✓
Has customizable notifications	✓
has clipboard warnings	✓
has on-device machine learning	✓
has location privacy options	✓
has camera/microphone privacy options	✓
Supports widgets	✓
has theme customization	✓
has focus modes	✕
has dark mode	✓
supports split screen	✓
has full-page screenshots	✓
supports slow-motion video recording	✓
Has sharing intents	✓
has Live Text	✓
has voice commands	✓
has an extra dim mode	✓
has Wi-Fi password sharing	✕
has battery health check	✕
Can play games while they download	✓
Has offline voice recognition	✓
can offload apps	✕
has PiP	✓
can create panoramas in-camera	✓
Is free and open source	✓

The software side of the device is notably broad, covering privacy and customization through features such as location privacy options, camera and microphone access controls, app tracking blocking, clipboard warnings, and dynamic theming with full theme customization and dark mode. It supports multi-user operation, customizable notifications, notification permissions, a media picker, widgets, split-screen multitasking, Picture-in-Picture, sharing intents, Live Text, voice commands, and offline voice recognition. Additional capabilities include on-device machine learning, device position tracking, full-page screenshots, slow-motion video recording, in-camera panorama capture, an extra dim mode, and the ability to play content while downloading. The platform is free and open source. Features not present include Mail Privacy Protection, cross-site tracking blocking, Quick Start, focus modes, Wi-Fi password sharing, battery health check, and the ability to offload apps.

Final Verdict

The Onyx Boox Note Air 4 C positions itself as a capable, feature-rich e-reader for users who need more than a basic reading device. Its 10.3-inch self-lit e-paper display at 300 ppi, combined with broad file format support, generous expandable storage, and an open-source platform that enables multitasking and on-device machine learning, makes it a well-rounded tool for readers, students, and document-heavy workflows. The trade-offs — notably its weight, the absence of fast or wireless charging, and the lack of a 3.5 mm audio jack — mean it is best suited to users who prioritize functionality and versatility over portability. For those who fit that profile, the Note Air 4 C delivers a solid and capable e-reading experience.