Onyx Boox Note Air 4 C Review: The Best Color E Ink Tablet for Most People

The Note Air 4 C looks almost identical to the previous model, which, in this case, doesn’t feel like a bad thing. The sleek aluminum frame and thin design give the device a premium feel. The tablet measures 8.90 by 7.60 by 0.23 inches (HWD) and weighs 14.8 ounces—the same dimensions as the Note Air 3 C, though the latter weighs more at 15.2 ounces. The $579 ReMarkable Paper Pro (10.8 by 7.80 by 0.24 inches, 18.6 ounces) is significantly larger and heavier, while the $399.99 Kobo Elipsa 2E (8.94 by 7.60 by 0.29 inches, 13.8 ounces) is the thickest but lightest of the bunch.

(Credit: Sarah Lord)

Like the previous version, the Note Air 4 C has a thick black bezel that surrounds the display. An additional gray bezel protrudes from the left side of the tablet and provides you with a place to hold it. The Boox logo is displayed in black at the bottom of the gray bezel.

The USB-C port for power and transferring files sits in the middle of the left side, with a microSD slot directly to its right. Both are flanked by speaker grilles. A power button with an embedded fingerprint sensor sits on the top left of the tablet, while the stylus connects magnetically to the right side. The fingerprint sensor works well, though the power button is slightly recessed and doesn’t offer any audible feedback when pressed. 

(Credit: Sarah Lord)

The tablet's back panel is matte black with an orange strip down the right-hand edge. It's slightly slippery to hold and an absolute fingerprint magnet. You’ll want to put a case on it for both grip and protection. If you buy directly from Boox, you can get a magnetic case along with extra pen tips included in the price. 

The tablet comes with a black stylus that supports 4,096 degrees of pressure and capacitive touch. It doesn't require charging and is similar to the styli of other E Ink tablets, like the ReMarkable Paper Pro.   

The company sells a premium stylus, the Pen2Pro, which you can bundle with the case and extra pen tips for $609.98, or purchase on its own for $79.99. The biggest difference between the two is that the Pen2Pro has an eraser button on the back. I generally prefer a stylus with an eraser, but I’ve found the included stylus to be perfectly serviceable without one.

Unlike smaller dedicated ereaders, E Ink tablets are generally not waterproof, and the Note Air 4 C is no exception. It lacks any kind of IP rating for dust and water resistance.

The Air 4 C uses the same 10.3-inch E Ink Kaleido 3 screen as its predecessor, which supports 4,096 colors. The more expensive Onyx Boox Tab Ultra C Pro ($649.99) also features the same display. It has a color resolution of 1,240 by 930 pixels for a density of 150 pixels per inch (ppi). Grayscale content has a sharper resolution of 2,480 by 1,860 pixels for a density of 300ppi, which is the same on across Amazon's latest Kindle devices. 

(Credit: Sarah Lord)

Colors on a color E Ink display—including the Air 4 C's—look different from traditional LCDs. The colors are visible but muted and look more like photos in print newspapers or old-fashioned newsreels. Reading and writing on color E Ink screens offers a nostalgic feel that I find charming, and they work particularly well with graphic novels and comic books. 

The handwriting experience is excellent. The combination of the pen and the slightly textured screen feels almost like writing on paper. There’s no noticeable lag between placing the pen on the screen and seeing the ink flow. 

One of the benefits of E Ink is that it is readable even in direct sunlight. The Air 4 C's display does show a slight bit of glare in sunny situations, but not enough to inhibit reading or writing. The included warm and cool LED front lights make sure that the display is readable in even the darkest rooms. 

(Credit: Sarah Lord)

Technically, you can watch movies and play games on the Air 4 C, but the experience isn’t pleasant. E Ink displays can’t keep up with the frame-rate requirements of video playback, so movies and shows look unnatural, blurry, and washed out.

The ReMarkable Paper Pro has a larger (11.8-inch) color display and is also an excellent note-taking device, but it only supports PDF and ePub files. The Note Air 4 C, by comparison, supports more than a dozen document formats and most major image formats.

The Onyx Boox Note Air 4 C is powered by an unspecified octa-core processor with 6GB of RAM, which is the same amount of memory as the Tab Ultra C Pro. This is an improvement over the 4GB found on last year’s model and is noticeable when performing everyday tasks. The tablet never stutters, even with multiple notes and apps open at once.

(Credit: Sarah Lord)

The Air 4 C has the same 64GB of storage found on the previous model, but you can always increase this via microSD card, though the company doesn’t specify the maximum card size you can use. Even so, 64GB is plenty of storage for notes, books, and other documents. You might reach the limit if you load the tablet with apps, but this isn't a tablet intended for heavy app users.

The device has a web browser, and it connects to the internet using dual-band Wi-Fi. The browser works well for reading the news or looking things up on Wikipedia, but don’t expect any E Ink tablet to replace your iPad or laptop. This is a device for those who want to limit distractions and focus on reading and writing. If playing games or watching videos is important to you, the $349 11th-gen iPad is a better bet. 

The Air 4 C has the same 3,700mAh battery found on the previous model. Battery life on E Ink devices generally lasts weeks, not hours, and I’ve found this to be true with the Air 4 C. I used it heavily for a week and it only lost about 25% of its charge. Your battery life will vary depending on your usage, as lots of note-taking and long reading and writing sessions drain the battery faster. 

The Note Air 4 C can get you through all of your classes in a day without causing battery anxiety, and it far outlasts the iPad.

The speakers are basic, don’t get very loud, and don’t do a good job of producing bass. I could hardly make out the bass in our test track, “Silent Shout,” by The Knife, and the volume didn't get loud enough to even fill a small room. The device lacks physical volume controls, so you need to swipe down from the top right corner to access the Control Center and its volume slider. This is awkward and time-consuming.

The tablet isn't really meant for blaring music. If you want to listen to audiobooks or recordings, you’re better off connecting headphones or speakers via the tablet’s Bluetooth 5.1 radio.

The Note Air 4 C runs on a highly customized and simplified version of Android 13. The company promises three years of firmware updates, but it’s unlikely that the tablet will ever get a full OS bump. The Air 3 C shipped with Android 12 and still runs it. Android 13 is almost three years old at this point, and while it should be safe to use for now, security concerns could be an issue in the future. 

(Credit: Sarah Lord)

Boox has simplified the software, eschewing the vertical menu from its Android 12-based user interface, instead adopting a more familiar, phone-like home page with apps and widgets. 

The home screen now consists of two widgets at the top: one for your library and one for your notes. You can see your last two open books in the library widget, along with thumbnails of your last three notes in the notes widget. You can click All at the top of the widget to see all of your books or notes, or click on one of the individual titles listed to jump right back into what you were doing. 

All your apps are below the widgets, including the Google Play Store, the NeoBrowser to get online, and the BooxDrop app (available for Android and iOS) to load books wirelessly onto the device. Swiping left brings up any additional apps that you’ve downloaded. A row of four apps is always present at the bottom of the screen. These include your Library, the Boox book store and its small selection of free classic books from Project Gutenberg, the Storage app (which tracks how much storage you have available), and the Settings menu. You can remove, add, or drag-and-drop any app into this row of apps. You can also navigate back to the home screen at any time by swiping up from the bottom center of the screen. 

(Credit: Sarah Lord)

The control center is available by swiping down from the top right corner and includes useful controls for the front light, volume, split-screen mode, auto-rotate, airplane mode, and more. You can add or remove settings from this list and customize it to your liking. The E Ink center is also available from this menu and can be accessed by swiping up from the bottom right of the screen. Here, you can adjust the refresh and color modes. The color modes include only Optimal or Vivid. I didn’t notice a huge difference between the two, but there’s also a Custom mode that allows you to play around with color brightness, vividness, and boldness yourself. 

The Refresh modes include HD, which is good for general text reading; Balanced, which has heavier ghosting but is better for thumbing through documents; Fast, which loses detail but is good for browsing websites; and Ultrafast, which has heavy detail loss but is meant for playing videos. I stayed on HD mode most of the time and found it worked well with just about all reading and internet browsing.

The built-in NeoReader app is one of my favorite ways to read, thanks to its superb customization options. Boox has made it even easier to home in on your perfect page by adding buttons for presets. In addition to the Original setting, a Bold setting turns all the text bold, and a Night setting automatically switches to dark mode. You can customize your own template to dial in margins, font, spacing, contrast, and more. The reading menu now has easy buttons for increasing or decreasing font size, though you can still go in and adjust it to the exact specification you like via the settings menu. 

(Credit: Sarah Lord)

The Air 4 C's color screen is great for taking notes and highlighting text. You can choose among 11 different colors for pens and highlighters, including blue, orange, pink, purple, red, and yellow. This gives you plenty of options for writing color-coordinated notes or highlights, which is perfect for studying. The native note-taking app is robust, with over 24 page templates, including musical notation, graph paper, line notes, and weekly planning. You can import your own custom template and use that, if you wish. Premium features include an audio recorder, a shape "perfector" to make your hand-drawn shapes even, scribble to erase, and text recognition. My only minor complaint is that I wish there were an auto-straighten feature for the highlighter, so I don't have to look at my uneven highlighting lines. Otherwise, annotating and writing notes in NeoReader is a breeze.

Getting your documents into NeoReader is easy. The BooxDrop app and its 10GB of free cloud storage make it simple to send documents wirelessly to your device. Unfortunately, NeoReader can’t open documents with Digital Rights Management (DRM), so you have to download and use third-party apps in order to read books from Kindle, Barnes & Noble, and other proprietary sources. These third-party apps, however, don't support all of the Air 4 C's note-taking functions. For example, I was able to use the Boox stylus to highlight text in my Kindle App, but I couldn't write or take notes with it (at least I didn't have to highlight with my finger). Most dedicated ereaders lock you into one ecosystem, so Boox’s access to the Play Store and its third-party software is exciting for those who have large libraries of books with DRM protections.

(Credit: Sarah Lord)

The Onyx Boox Note Air 4 C is a worthy successor to its excellent predecessor. It retains the premium design, large color E Ink display, and excellent stylus, while it updates the software and adds more memory to make it a more powerful device. We wish the speakers were a little better, but that's a minor quibble in light of its continued support for the Google Play Store and the access to third-party reading apps it enables. The Onyx Boox Note Air 4 C may be pricey, but we think it is the color ereader to get and is our Editors’ Choice winner.