Boox Note Air4 C Review

Design and Build

The Note Air4 C (NA4C) uses exactly the same chassis as its predecessor, the Note Air3 C (NA3C), the only difference being the location, size, and colour of the Boox logo on the left-hand bezel.

It has a metallic shell, and a glass screen. This makes it feel quite cold and rigid, much like a hard slate, but also gives the impression of tough build. I can attest to the durability of this chassis design having lugged around and frequently used the NA3C for almost 12 months – it is still working absolutely fine and does not have so much as a scratch on it (however, the folio should take some of the credit for this).

It is really well-built with no visible imperfections, and has nicely rounded corners, with a slight curve on the edges. Although it feels solid and robust, it does have quite a bit of heft at 420g (not including the folio). It is not uncomfortable to hold or lift, but also not something you would want to be carrying for long periods with one hand.

There is a USB-C port on the left-hand edge, which can be used for both charging and data transfer. And on the top edge (level with the top-left corner of the screen) is the power button, which doubles as a fingerprint scanner. The right and bottom edges are smooth with no ports or buttons.

As I’ve said in my previous reviews of devices using this chassis, the location of the USB port on the left edge is somewhat mind-boggling. This is because it is adjacent to the spine of the folio, which means you cannot charge the tablet with the folio closed. There is also a risk of damaging the cable/port by inadvertently trying to close the folio when a USB cable is plugged into it. The top, bottom and right edges of the tablet are all accessible with the folio closed and (in my opinion) would be a much better location for the USB port.

The location of the power button/fingerprint scanner also slightly frustrates me (although I think this is a “me problem” rather than a design flaw).

It is located on the top edge, around thumb’s width from the left (and level with where the screen begins). Personally, I find myself always gravitating to the far left of the top edge to activate the power button. Then, I realise the power button isn’t there and have to move my finger around 2.5cm to the right to locate it. You’d think I’d get used to it, but after 12 months of using this chassis design, I still cannot remember where the power button is on first try! I think it’s because I assume it will be level with the thicker left bezel, and there is also there is an orange mark (actually the start of the orange stripe that runs down the rear of the tablet) that diverts my attention.

The power button/fingerprint scanner is flush with the top edge (rather than jutting out slightly), which adds to the sleek look of the tablet, but can make it slightly more difficult to locate with your fingertips and press in.

Despite these two irritations, the design and build of the Note Air4 C is exceedingly good. It is well machined, with no audible creaking or rattling and feels robust and durable, if a little heavy. Aesthetically speaking, it is very nice to look at, although perhaps not quite as elegant nor visually appealing as the likes of the reMarkable 2, or the Boox Go 10.3.

Hardware Specs

Under the bonnet is a Qualcomm Snapdragon 750G octa-core processor with a clock speed of 2GHz.

There’s also 6Gb RAM and 64Gb of storage capacity (which can be extended up to 2Tb, using the MicroSD card slot).

In addition, there’s a graphics processor (GPU), which is used to run Boox’s proprietary Super Refresh technology (BSR). Essentially, this means that third-party apps can be configured to run at faster refresh rates than e-ink screens were originally designed for, which can make tasks like web browsing on e-ink a more pleasant experience.

SIDENOTE: Although BSR means that performance of third-party apps is much-improved compared to e-ink tablets that do not use this proprietary technology, the performance is still nowhere near what you would expect from an LCD/OLED screen. For certain tasks (such as video) there are still inherent issues with image quality and ghosting. However, apps that do not require super-fast movement (such as scrolling down a webpage) are much smoother.

Using the Geekbench 6 CPU Benchmark app, the NA4C scored 746 in the single-core test, and 1775 in the multi-core test (the mean average of three tests).

Of course benchmarks are only useful if you have something to compare the numbers, so check out my full CPU performance benchmarks here (the NA4C performed really well).

On the whole, the NA4C has some beefy specs for an e-ink tablet, and has the potential to easily multitask several third-party apps, as well as its own native apps.

Screen

The screen is 10.3″ (around A5-sized) and has colour capabilities (Carta 1200 with Kaleido 3). It is flush with bezels.

It has a monochrome resolution of 1860 x 2480 (300dpi) and a colour resolution of 930 x 1240 (150dpi).

Kaleido 3 – and colour e-ink in general – does have some compromises (which I explore here), but on the whole the NA4C implements colour really well.

One of the drawbacks of Kaleido 3 is that it makes the screen appear several shades darker than their monochrome counterparts. Monochrome e-ink tablets have a visibly ‘whiter‘ background. On the NA4C, I felt that the screen was slightly darker/less white than other Kaleido 3 tablets I’ve reviewed, when the frontlight was turned off.

However, this inherent ‘darkness‘ is mitigated when the frontlight is turned on. In addition, the frontlight on the NA4C seems brighter and more intense on than previous models.

There are touchscreen capabilities, and a Wacom EMR layer (so any Wacom-compatible stylus will work fine with it).

And there is “paper-like” film on the surface, which makes writing with stylus feel slightly rougher and grainier rather than a glass-like texture (although the screen still feels smooth to the touch).

Other than the inherent darkness and other Kaleido 3 limitations (which is an issue with the underlying e-ink technology, and present on all colour e-ink tablets), the screen on the NA4C is really nice. Although the tablet can be viewed clearly in well-lit environments, it is likely that you will need to activate the frontlight (if only on a low setting) to illuminate the screen enough to make it comfortable to work with in dimmer conditions. Colours look good (again, in the context of the limitations of Kaleido 3), and both text and images render really well.

Writing feel

The “paper-like” film on the top of the screen produces a somewhat rough and grainy feel as the stylus nib glides over it.

It also makes a satisfying audible scratching sound – it is not glass-like or slippery like some tablets I’ve reviewed.

The screen is hard, providing a rigid and stable canvas but the nib is soft, so there is no harsh tapping sound when it hits the screen. The nib also tapers to a small rounded point, which provides a decent level of precision when writing. However, because the frontlight layer occupies the space between the surface layer and the e-ink layer, there is a minuscule gap between where the stylus touches the screen and where the strokes appear, almost as though you are writing slightly below the screen. For new users, this is so small that it may even be imperceptible, but for existing e-ink users that are accustomed to writing on a tablet without a frontlight, the difference can be a bit of a shock, and can require some time to adjust. I explore the advantages and disadvantages of frontlights here.

There is very little perceived lag when writing – as you move the stylus over the screen, the strokes appear almost immediately.

And, both pressure and tilt sensitivity have been implemented in the native note-taking app (dependent on which brush/pen tool is selected) and work really well – see my review of the Boox firmware below for more info.

Overall, I really enjoy the experience of writing on the NA4C. It does not feel quite as precise as non-frontlit tablets I have used (I do notice the difference) but out of all e-ink tablets that do have a frontlight, the writing feel of the NA4C is one of the best.

Hardware features

As well as the underlying hardware specs, the NA4C has some additional hardware features that make the tablet more versatile.

As standard for most e-ink tablets, there’s support for both Wifi and Bluetooth connectivity. As well as connecting headphones, Bluetooth can also be used to connect other peripherals, such as third-party keyboards (there is no official keyboard folio for the NA4C).

For further connectivity, the single USB-C port supports On-The-Go (OTG) connections, which means you can hook up a USB hub for the connection of peripherals and mass storage devices (hard drives, USB sticks etc.) In addition, there’s a MicroSD card slot, which can be used for additional storage capacity.

There’s a G-Sensor for automatically reorienting the screen between landscape/portrait when you rotate it physically.

And there’s also dual speakers and microphone. The microphone can be used for recording voice notes in the native note-taking app (and other third-party apps) or for recording a meeting. As well as system sounds (such as notification alerts), the speakers can be used for Text-to-Speech (TTS) in the native reading app, or even for listening to music/videos. However, don’t expect too much from the onboard speakers and mic – they’re very basic additions that are great for simple everyday use, but are not going to produce anything of production quality.

As mentioned previously, there’s also a fingerprint scanner built into the power button. If you’ve set up a password/PIN to lock the screen on the NA4C, you can also configure the tablet to accept your fingerprint instead. This can make accessing the device quicker and easier – you simply put your finger on the power button rather than having to type in the password, using the touchscreen.

Overall, the additional hardware features provided on the NA4C offer several additional use cases for the tablet beyond simply reading and note-taking. For example, you can record meetings and voice reminders, or listen to podcasts using Bluetooth headphones or the integrated speakers. You can increase the storage capacity using MicroSD or USB. You can even connect a Bluetooth keyboard for typed input.

Battery

The NA4C has a 3700mAh battery.

As mentioned previously, e-ink tablets with a dedicated GPU and Super Refresh technology are going to drain the battery much quicker than their less power-hungry counterparts.

Of course, the battery life can be improved by turning off the frontlight and wifi/Bluetooth if they’re not required.

Comparatively-speaking, the battery performs a better than the NA3. However, battery life is much shorter than e-ink tablets that do not have BSR, or a frontlight, which can last for a week or more.

The table below shows how much battery is depleted by performing certain operations for an hour.

Test (1hr)	NA4C (% battery used)
Note-taking	4%
Reading	2%
Wifi On	+0%
Frontlight (medium)	+1%
Frontlight (full	+5%

So, you could expect to drain about 4% of the battery per hour when note-taking, and 2% per hour when reading. If the frontlight is on a medium setting, expect to add another 1% per hour, and if it is on full, add an extra 5% per hour. Having Wifi on or off doesn’t make much of a difference (but remember this test was only an hour long, so it may make a difference over longer periods).

I calculate typical battery life from these figures by assuming 3 hours of note-taking and 2 hours of reading each day, with the Wif turned on for 3 hours, the frontlight on medium for 2 hours, and on full for 2 hours.

For the NA4C, this works out at about 28% of battery use per day, which would give you 3.6 days of use before it needed to be recharged.

For a tablet with BSR, this is really good, although not as long as you would get with a non-BSR tablet – you can see how it compares to other tablets here.

Accessories

The NA4C shipped with a folio cover, stylus and 5x spare marker tips/nibs.

At the time of writing, these are the same accessories that are provided if you buy an NA4C from the official Boox Store or Boox Euro Store.

If you buy from Amazon, although the price is the same, you only get the tablet and stylus and have to buy the folio and marker tips separately. Whilst you get more thrown in when buying direct from Boox, there are advantages to buying from Amazon, including fast shipping and a quicker, easier, and less costly returns process.

Stylus

The NA4C ships with the Boox Pen Plus stylus, which I am really rather fond of because of its minimal design.

It is almost cylindrical, with one side flattened to prevent it rolling on uneven surfaces. There are vertical grooves down the side, which help to provide a decent grip (and also aid roll-prevention). I find that the stylus is nicely-weighted (not too heavy, not too light), which makes for a comfortable hold and a pleasant writing experience.

There’s no bells and whistles on the Pen Plus, such as an eraser on the top or a button on the shaft – and, for me, this is a pro rather than a con. My fat fingers always seem to inadvertently activate side buttons without meaning to, and Boox’s scribble-erase feature is quicker than turning the stylus upside-down to use the physical eraser. However, this is my own personal taste – some people do like to have a physical eraser, and for these users Boox sell the Pen2Pro, however there is currently no option to buy the NA4C with the Pen2Pro instead of the Pen Plus.

Because Boox tablets use Wacom-EMR technology, it is possible to use third-party Wacom-compatible styluses with the NA4C. Although the eraser on such styluses should work fine, I can find no configuration settings in the Boox software to configure the action of additional buttons.

The Pen Plus uses soft, replaceable nibs, which produce a nice tactile writing feel with the screen (see my remarks about the writing experience above) but they do wear down with use. And if you do a lot of writing like me, you will probably need to replace the nib every couple of months, which is an ongoing cost. However, this is true for the majority of e-ink tablets, barring Supernote styluses, which use ceramic tips that never wear down – unfortunately, these harder tips are not recommended for use with non-Supernote tablets because of the risk of scratching the screen.

The stylus attaches magnetically to the right edge of the tablet, which offers a fairly sturdy hold, although a quick jolt of the tablet does result in it falling off. However, during transit, the folio (see below) has a magnetic flap on it to hold the stylus more securely.

On the whole, I wouldn’t go as far to say that the Boox Pen Plus is the best stylus I have ever used, but it is right up there near the top.

Folio

The folio is also rather nice, although there are a couple of things I’m not too keen on.

The exterior is hard and padded to provide protection, and the textile used on the interior has a softer feel.

The tablet attaches to the folio magnetically, which provides a very strong grip. With enough force, it will pop out of the folio, but I would say that this is unlikely in most day-to-day situations. For extra hold, the folio has a magnetic flap on the right-hand side which performs the dual purpose of holding the stylus in place, and keeping the folio close during transit.

However, despite the practicality of the magnetic flap when the folio is closed, I do find it slightly irksome when the folio is open and I am using the tablet. It just looks a bit unsightly sticking out on the right, and folding it under the tablet/folio results in the tablet being uneven and wobbling slightly. And sometimes the flap curls upwards and snaps to the screen.

However, this minor inconvenience is more than made up for by the innovative way that the folio can be converted into a stand. There are various grooves on the folio separating the padded areas, which can be folded into various configurations.

To be 100% honest, I found the the landscape configurations a little shaky and unstable. They’re certainly not unusable but there is a bit of unwanted movement when you tap the screen. But the portrait configuration is very stable and very practical. I’ve used it in this way for both referring to a document when I am typing on my laptop, and for actually typing a document on the NA4C itself (using a Bluetooth keyboard).

In summary, despite a few small irks, the NA4C folio is exceedingly good in terms of both protection and usefulness. And it also looks really nice. However, the padding and the magnets do make it a bit heavier than other folios in this size category.

Software

My review of this tablet should be read in conjunction with my review of the current firmware (see table below), which includes aspects such as the Operating System, User Interface, and Native Apps.

The hardware and software reviews have been separated because the firmware used at the time that this review was written may not be the same firmware being used currently. This could result in the review quickly becoming outdated. Also, as several tablets may use the same firmware, this would mean going back and updating every single tablet review from a particular manufacturer to account for the new firmware. By splitting them up, if there is a firmware update, I am able to make the updates on a single page.

Current versions of this brand’s firmware are shown in the table below, along with the tablets running them.

My rating	Firmware version	Tablets using this firmware
	4.1 (current version) Aug 2025	Boox Go 10.3 Boox Note Air4 C Boox Go 7 Boox Note Air3 Boox Note Air3 C Boox Go Color 7 Boox Note Air5 C Boox Palma 2 Pro
	4.0 (current version) Oct 2024	Boox Note Max Boox Tab Ultra C Pro Boox Tab X Boox Tab X C Boox Tab Mini C Boox Tab Ultra Boox Max Lumi 2 Boox Tab Ultra C Boox Note Air2 Plus Boox Note 5
Older Boox firmware versions may be found here

Brand

For some people, it is also worth considering the brand as whole, including aspects like customer service, ecosystem, values, and criticisms.

My full overview of the Boox brand can be found here, but I have provided a summary below.

Final Verdict

The NA4C is a very versatile and powerful e-ink tablet.

It is well-constructed, sturdy, and durable, although it does have a few questionable design decisions, such as the location of the USB port.

It has a decent CPU and memory, which performed really well in the benchmark test and, along with the the GPU/BSR, should be able to handle most tasks. The screen is also high-quality, although it does have the inherent “screen darkness” that is present on all Kaleido 3 tablets, which means that the frontlight may need to be turned on more frequently.

Combined, BSR and regular frontlight usage are a power drain which negates one of the benefits of e-ink screens, namely low power consumption. Non-BSR tablets only require recharging about once a week, whilst the NA4C will only last a couple of days with average use.

Microphone, speakers, USB/OTG, Wifi, Bluetooth, and MicroSD all provide additional options for how the NA4C is used. You can record voice notes, connect up a Bluetooth keyboard, store your important files on MicroSD card (or USB stick, or a third-party cloud) or listen to the radio whilst working.

The stylus is decent, and the folio provides both protection and flexibility.

Together with Boox’s very comprehensive reading and note-taking apps, as well as the ability to install third-party apps, Boox have taken a multi-faceted approach to their e-ink tablets that makes them adaptable to several different use cases.

The Boox Note Air4 C is one of my top picks, and highly recommended.

Tablet Overview