Onyx Boox Nova Air C review: Android-based color e-book reading


Images: Sandra Vogel / ZDNet

onyx is an established manufacturer of e-ink Tablets that, thanks to the implementation of Android, can both allow pen input and run third-party applications. Onyx devices come in a variety of sizes for a range of use cases. Most recently, I looked at a pair of e-readers/content creation devices – the 13.3-inch Boox Max Lumi2 and the 10.3-inch Boox Note Air2.

Now Onyx has taken on the challenge E Ink Kaleido Plus Color screen that offers 4,096 colors on a low-power panel. The 7.8 inch Onyx Boox Nova Air C pairs this with Android 11 and pen-based input. It promises 4 weeks of battery life in standby mode and costs $419.99 / £399.99.


  • E Ink color screen
  • Android 11 and Google Play Store
  • Bundled pen
  • Good battery life

don’t like

  • Cover is an optional extra
  • No MicroSD card slot for storage expansion

Aside from the color on its screen when the device is off, the Nova Air C looks like many other e-readers. It measures 136.5mm wide, 194mm deep and 6.3mm thick and weighs 235g without the optional cover ($59.99/£53.99). There’s a Boox mark along the bottom bezel and just enough side bezel to hold the device securely without touching the screen. The workmanship feels robust and there are no corners or edges in terms of quality.

There is only one button on the top edge that turns the device on and off. On the bottom edge are a pair of speakers and a USB-C port for charging. The bezels lack buttons or touch controls – you either tap the screen or use physical page turning buttons on the optional casing to navigate.

The Nova Air C is powered by a Snapdragon 662 Chipset with 3GB of RAM and 32GB of internal storage. There’s no MicroSD card slot to expand the storage, which is arguably a concern given this device’s potential to unite all your e-books and audiobooks, and thanks to its pen support it functions as a productivity tool to some degree. based input.

For connectivity, there’s Wi-Fi 5 (802.11ac) and Bluetooth 5.0, so earbuds can be paired if the internal speakers are too intrusive for your location. I found the speakers delivered good quality audio for listening to material such as podcasts. The USB-C port is used for charging and can also be used to connect the Nova Air C to your computer when it’s available for drag-and-drop file transfers.

The Nova Air C’s 2,000mAh battery lasts four weeks on standby, according to Onyx. Since e-ink screens only consume power when they are being refreshed, the power consumption is lower than that of a regular tablet, phone or laptop. During testing, I was able to read ebooks regularly for a week between charges, although I made sure to turn off Wi-Fi when not needed to conserve battery power. There’s no fast charging here, so you’ll need to keep an eye on the power level and make sure there’s enough time for a boost when it gets low.


The cover for the Boox Nova Air C is an optional extra that costs $59.99 or £53.99.

Image: Onyx

It’s unfortunate that the device cover has to be purchased separately at a rather hefty $59.99 / £53.99. Buy it and you’ve got a total spend of $479.98 / £453.98. I’m not a fan of the silver color of the case, but the magnets that attach it to the Nova Air C are strong. You could search the web for a suitable alternative protection if the budget is tight and you’ll just miss a couple of physical page-turning buttons.

Luckily, the stylus needed to get the most out of the Nova Air C comes with the device itself. It attaches to the right side of the reader via magnets, and while the grip is fairly strong, it’s not secure enough to be a permanent solution. The case doesn’t have a loop or slot to hold the stylus, which meant I always had to remember to carry it when taking the Nova Air C anywhere I likely needed the stylus. In the long run that would probably be a problem for me. A more reliable solution is needed, even if it means adapting the design of the pen or tablet to accommodate a housing on the device.

The 7.8-inch screen delivers two different pixel densities thanks to the workings of the Kaleido Plus display. In color mode, the resolution is 468 by 624 pixels, giving a pixel density of 100 dpi, while in monochrome mode it increases to 1,404 by 1,872 pixels and a pixel density of 300 dpi.

According to Onyx, Kaleido Plus offers 30% improved contrast in mono mode compared to its predecessor, as well as 30% improved contrast in color mode and 15% color improvement. These improvements come because touch response is now built into the screen itself, rather than requiring a separate layer over the display, which inevitably creates a visual barrier to the display itself. E Ink calls this ability “On-Cell”.

Without two devices side by side, it’s difficult to evaluate these claims in practice, but my everyday experience has been positive. I found reading e-books completely satisfying, and page turning is just as quick and clean as I would expect from any e-reader device. The 7.8-inch screen size is good too – just about the sweet spot for reading. I downloaded both the Kindle and Kobo reader apps, as well as the Libby app used by my public library. Everything worked fine. There are numerous fonts and sizes to choose from and the device supports a range of document formats: PDF (confluent), PPT, EPUB, TXT, DJVU, HTML, RTF, FB2, DOC, MOBI, CHM. It also supports PNG, JPG, TIFF, BMP images, WAV and MP3 audio, and DRM via 3rd party apps.


Color – but not in the way you’re used to from a tablet with a backlit LCD or OLED screen.

Images: Sandra Vogel / ZDNet

The color screen meant I enjoyed magazines through my public library’s lending service as much as reading e-book loans. However, the E Ink Kaleido Plus screen is nowhere near as good at color reproduction as a regular tablet or phone. Don’t set your expectations too high.

Android 11 provides access to the e-reading apps I have installed, as well as the rest of the Google Play Store. Besides that, there are some pre-installed Onyx apps like a dictionary and the Neo Browser Web browser, Boox e-book store and note-taking app that lets you create and save handwritten notes with the stylus. The pen has 4,096 levels of pressure sensitivity and there are plenty of brushes, line widths and color options to work with.

Handwriting to text conversion is supported, and I found it to be fairly accurate. You can also record spoken content – the microphone is at the bottom – and the resulting audio can be embedded in a document.

To help users circumvent the relative complexity of the offering, a small circle can be set to always be present on screen, and tapping it brings up nine shortcut buttons that can be customized for specific functions like application launches. Still, the user interface is unlike any other device, and there are so many features and customization options that it’s going to take a while to exhaust all the rage. This isn’t a criticism – it just underscores what a well-equipped device this is.


The Onyx Boox Nova Air C is an interesting mix of e-book reader, content creation device and tablet, with Android 11 providing a large selection of apps. It’s well made, has a long battery life and comes with an included stylus.

The lack of a MicroSD card slot to expand the 32GB of internal storage is disappointing. The colored E Ink display isn’t as vivid as that of a regular tablet or phone, and screen updates are slow in comparison. The Nova Air C is in no way a replacement for either device, but the addition of a color display brings a welcome new dimension to the Onyx Boox range that should please fans of its hybrid consumption/content creation approach.

Onyx Boox Nova Air C specifications


E Ink Kaleido Plus, 7.8 inch, 4096 colors, touch (inductive Wacom + capacitive), 1872 x 1404 (300 ppi/100 ppi in color mode), SNOW Field function


moonlight 2


Qualcomm Snapdragon 662 Mobile Platform






speaker, microphone

cable connection

USB Type-C

Supported file formats


Wireless Internet access

WiFi 5 (802.11ac)




2000mAh lithium polymer

operating system

Android 11


136.5mm × 194mm × 6.3mm





In the box

Onyx Boox Nova Air C, user manual, stylus, USB cable, warranty card


$419.99 / £399.99

to examine alternatives

Backlight-free, low-power consumption technologies for color e-book readers are an emerging field. For example, E Ink is researching a technology called Advanced Color ePaper (ACeP), although it’s currently only available as Evaluation kit for $799and launched a successor called Kaleido Plus in April kaleido 3. Another promising but still unfulfilled development is that of TCL NXTpaper Mid, which uses a transflective LCD. An alternative e-ink technology that has made it to the market OF (Display Electronic Slurry), as seen in the Reinkstone R1.


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