The Boox Note Air 4 C is the most capable Android e-ink tablet on the market right now, and it earns that title by being a genuinely usable Android device first and a note-taking slate second. If you want one gadget that runs Kindle, Word, a real web browser, and a pressure-sensitive notebook app without booting into a laptop, this is it. But the color E Ink screen is muted, the battery drains faster than a Kindle Scribe, and Onyx’s software still has rough edges that a reMarkable or Supernote buyer would never tolerate.
Key takeaways
- 10.3-inch Kaleido 3 color E Ink panel, 300 PPI in black and white, roughly half that effective resolution for color content.
- Full Android 13 with Google Play Store access — this is the biggest differentiator from the Kindle Scribe, reMarkable Paper Pro, and Supernote Manta.
- Boox Pen 2 Pro included, 4096 pressure levels, no charging required (EMR technology), magnetic dock on the side.
- Battery lasts roughly 4-6 days of mixed reading and writing, or several weeks in pure standby with Wi-Fi off — far short of the Kindle Scribe’s multi-week claims.
- No subscription required for note-taking or sync, unlike reMarkable’s optional $2.99/month Connect plan; on-device OCR and export to PDF, PNG, TXT, and DOCX come standard.
- $549.99 with the pen included, which undercuts the reMarkable Paper Pro bundle but costs more than the base Kindle Scribe.
What the Note Air 4 C actually is
Onyx has been building Android e-ink tablets since before “digital paper” was a marketing category, and the Note Air line is its mainstream flagship — the one meant to compete with the reMarkable and Kindle Scribe rather than the more niche Tab Ultra or Max series aimed at power users who want a bigger canvas. The Note Air 4 C is the color version of last year’s Note Air3 C, built around the same 10.3-inch Kaleido 3 panel that Onyx uses across several 2024 devices, paired with a faster octa-core processor, 8GB of RAM, and either 128GB or 256GB of storage.
That storage number matters more here than on a reMarkable or Kindle Scribe because this device runs actual Android apps. You are not limited to Onyx’s note and reading apps — the tablet ships Play Protect certified, meaning the real Google Play Store is present out of the box, not a sideloaded workaround. That single fact is why this review exists as a distinct category from the rest of the e-ink note-taking field: it changes what the device is for.
Build and hardware
The chassis is aluminum, about 5.8mm thick, weighing approximately 420g — noticeably heavier than the reMarkable Paper Pro’s 405g but with a similar in-hand feel because the weight is distributed evenly across a flat slab rather than a tapered wedge. There’s a single USB-C port, a power button doubling as a fingerprint reader on some configurations, and stereo speakers plus a microphone, which the reMarkable and Supernote Manta both lack entirely. That means you can actually take a Zoom call or play a podcast on this thing, however strange that sounds for an E Ink device.
The front light uses a 36-LED array split between warm and cool tones, adjustable independently, which is standard for Onyx’s higher-end models and noticeably more even than the lighting on the Kindle Scribe.
The screen: where color E Ink still compromises
Kaleido 3 is the third generation of E Ink’s color filter layer technology, and it is better than Kaleido 2 without being close to a tablet LCD. The panel is 300 PPI for black-and-white text and line art — sharp enough that handwriting and small fonts look clean, comparable to the Kindle Scribe’s Carta 1200 display. Color content is a different story: the filter layer sits on top of the monochrome pixels, which halves the effective resolution for color and mutes saturation considerably. Reds look brick-toned, greens lean olive, and anything with fine color detail — a photo, a highlighted PDF with multiple colors — looks closer to a newspaper comic strip than a printed page.
This is not a Boox-specific flaw. The reMarkable Paper Pro uses a similar generation of color E Ink and has the same washed-out characteristic. If you are buying either device expecting vibrant color, you will be disappointed. What color E Ink is genuinely good for is color-coding: highlighting a PDF in yellow versus green, using colored pens to separate sections in handwritten notes, or telling apart tabs in a reading app at a glance. Treat color as an organizational tool, not a display upgrade, and the Note Air 4 C’s screen makes sense.
Refresh rate and ghosting
Onyx gives you four refresh modes, roughly labeled HD, Balanced, Speed, and Ultrafast in the settings menu. HD mode gives the cleanest image with a full-screen flash refresh and is what you want for reading. Balanced mode is the default for note-taking — it refreshes only the affected screen region and keeps ghosting (the faint shadow of previous screen states) to a tolerable level. Speed and Ultrafast modes drop to fewer gray levels for scrolling web pages or watching video, and ghosting becomes obvious within a few page turns, requiring a manual full refresh. This tradeoff — speed versus clarity — is inherent to E Ink and identical in kind to what you’d see on a Kindle Scribe or Supernote Manta, though Onyx’s implementation gives you more granular control than either competitor.
Writing experience: pen feel and latency
The bundled Boox Pen 2 Pro uses EMR (electromagnetic resonance) technology, meaning it needs no battery and pairs instantly through the digitizer, the same approach reMarkable and Kindle use. It supports 4096 levels of pressure sensitivity and tilt detection, and it has two customizable side buttons plus a magnetic attachment point on the tablet’s right edge — a feature the Kindle Scribe’s Premium Pen also has, but the reMarkable Marker Plus does not (its eraser is built into the pen’s tail instead).
Onyx advertises 14ms latency in its fastest response mode. In practice, sustained cursive writing at normal speed feels responsive and close to a fast ballpoint pen, but if you write quickly in short bursts — signing your name, quick check marks — you can still perceive a flicker of lag that the reMarkable’s dedicated, single-purpose processor handles slightly more smoothly. This is a consistent pattern across Onyx’s lineup: the extra overhead of running full Android costs a small amount of pen responsiveness compared to a device built for nothing but writing.
Palm rejection is reliable in the native NeoStudio note app and in most well-optimized third-party apps, but it is inconsistent in some Play Store apps that were never designed with a stylus digitizer in mind. If you plan to write extensively inside apps like Google Keep or Notion rather than Onyx’s own software, test palm rejection before committing to a workflow.
Software: Android is the whole pitch
This is the section that actually separates the Note Air 4 C from every other device in this review category. The Kindle Scribe runs Amazon’s closed Kindle OS. The reMarkable Paper Pro runs reMarkable’s own closed OS. The Supernote Manta runs a modified Android build with no Google Play Store access at all — you can sideload APKs, but there’s no App Store convenience. The Note Air 4 C runs Android 13 with full, certified Google Play access, meaning you install the actual Kindle app, the actual Google Docs and Word apps, Chrome, Spotify (for audio only, obviously), and any PDF annotation tool you already use on your phone.
That access comes with real friction. Android apps built for full-color, fast-refresh LCD screens do not know how to behave on an E Ink panel — video content is choppy by nature of the hardware, animations that assume 60fps look like slideshows, and some apps’ dark mode inverts colors in ways that look worse on E Ink than a plain white background. Onyx’s launcher includes a per-app refresh mode override to mitigate this, and it works, but it’s a setting you’ll be tweaking app by app rather than something the system handles invisibly.
Onyx’s own apps — NeoStudio for notes and NeoReader for documents — are mature and well-designed at this point. NeoStudio supports layered notebooks, shape recognition, a lasso tool for moving handwritten content, and on-device handwriting-to-text conversion (OCR) that supports dozens of languages with solid accuracy on clear handwriting. Export options include PDF, PNG, TXT, and DOCX — more export flexibility than the Kindle Scribe offers natively, and on par with what reMarkable provides through its Connect subscription.
No subscription tax
This matters for the value conversation. reMarkable’s core hardware works without a subscription, but its handwriting conversion, unlimited cloud storage, and PDF-to-Word export all sit behind Connect at $2.99/month or roughly $30 upfront for a year. Onyx bakes equivalent features — cloud sync, OCR, format conversion — into the device with no recurring fee. If you’ve been avoiding a reMarkable specifically because of subscription fatigue, that’s a legitimate reason to look at Boox instead.
Battery life: the real tradeoff for Android
Running a full Android stack with Play Store background processes costs battery, and this is where the Note Air 4 C loses the most ground to its purpose-built competitors. The Kindle Scribe, with no app ecosystem to feed, can genuinely stretch into weeks of use on a charge for typical reading and occasional writing. The reMarkable Paper Pro lands around two weeks under normal use. The Note Air 4 C, with its 3700mAh battery, realistically delivers four to six days of mixed reading, writing, and light app use before needing a charge — closer to a basic Android tablet’s cadence than to a dedicated e-reader’s. If you disable Wi-Fi and background sync and use it purely as a distraction-free notebook, you can push that closer to two weeks, but then you’re not using the feature that justifies the higher price.
Note Air 4 C vs the competition
| Device | Screen | OS / App access | Pen (included) | Battery (typical use) | Price |
|---|---|---|---|---|---|
| Boox Note Air 4 C | 10.3″ Kaleido 3 color, 300 PPI mono | Android 13, full Google Play Store | Boox Pen 2 Pro, 4096 levels, EMR | 4-6 days mixed use | $549.99 |
| Kindle Scribe | 10.2″ Carta 1200, monochrome, 300 PPI | Closed Kindle OS, no app store | Premium Pen, EMR | Multiple weeks | $399.99 (16GB) |
| reMarkable Paper Pro | 11.8″ color E Ink, ~229 PPI | Closed reMarkable OS, no app store | Marker Plus, EMR (some bundles extra) | ~2 weeks | $579 (with Marker) |
| Supernote Manta | 10.7″ color E Ink, 300 PPI mono | Modified Android, no Play Store (sideload only) | Supernote pen, EMR, included | ~2-3 weeks | $529 |
Who should actually buy this
Buy the Note Air 4 C if you want one device instead of two
If your actual goal is replacing both a Kindle and a paper notebook, and you don’t want to carry a phone or laptop just to check email or read a Google Doc, the Note Air 4 C is the only device in this comparison that does all three without workarounds. Anyone already invested in Google’s ecosystem — Docs, Drive, Gmail — gets native access here that no competitor offers.
Buy the Kindle Scribe if you already live in Kindle
If your reading library is entirely Amazon and your note-taking needs are lightweight — margin notes, to-do lists, the occasional sketch — the Scribe is cheaper, lasts far longer on a charge, and has a simpler interface with fewer settings to manage. It is not for you if you want to run any app beyond Amazon’s own software; there is no workaround for that limitation.
Buy the reMarkable Paper Pro if paper feel matters more than an ecosystem
reMarkable’s pen-to-screen friction and single-purpose focus still produce the closest experience to writing on actual paper of anything in this category, and its interface has the least amount of digital clutter. It is not for you if a $2.99/month subscription for full functionality is a dealbreaker, or if you want any access to third-party apps — there is none, by design.
Buy the Supernote Manta if you want the cleanest note-taking software, no ecosystem lock-in
Supernote’s software is widely regarded as the most polished pure note-taking experience on E Ink hardware, with excellent PDF annotation and a keyboard-friendly file browser. It is not for you if you want Play Store access — Supernote deliberately omits it, and sideloading Android apps on it is a fragile, unsupported process compared to Boox’s native support.
Skip all four if you mainly want a color reading device
None of these tablets render color the way a phone or iPad does. If vivid color output matters more than pen input, a standard color LCD tablet will serve you better, and you’ll save money by not paying for E Ink’s glare-free, battery-sipping advantages you won’t use.
Where the Note Air 4 C falls short
Onyx’s build quality is solid but its software update cadence has historically been less predictable than Amazon’s or reMarkable’s — firmware updates arrive in batches with changelogs that read like a work-in-progress rather than a finished product. The speaker and microphone are genuinely useful for note-to-audio recording during meetings, but voice call quality through the built-in mic is mediocre. And because the tablet supports full Android multitasking, it’s also easier to turn into a productivity trap: notifications, app icons, and a home screen that behaves like a phone can undercut the distraction-free promise that draws people to E Ink devices in the first place. You can disable most of this in settings, but it takes deliberate configuration rather than arriving that way out of the box.
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