Frame

What this Boox Note Air 4 C review covers

This Boox Note Air 4 C review is built from daily use of the device over a multi-month stretch alongside the rest of the Onyx Boox lineup and the closed-software alternatives (reMarkable Paper Pro, Kindle Scribe Colorsoft). The Note Air 4 C is Onyx’s current 10.3-inch color writing flagship, launched in late 2024 to replace the Note Air 3 C. The hardware is a Kaleido 3 color e-ink panel paired with the standard Boox Android stack and the Pen2 Pro stylus.

The argument the Note Air 4 C makes is straightforward: a writing-and-reading tablet that can also run any Android app you want, at a price ($499) below the reMarkable Paper Pro and the Kindle Scribe Colorsoft. Whether that argument lands depends on whether you want the device to enforce focus or to do everything.

Specs

Boox Note Air 4 C specs at a glance

Spec Value
Display 10.3-inch Kaleido 3 color e-ink, 300 ppi mono / 150 ppi color
OS Android 13 with Google Play installed
Stylus BOOX Pen2 Pro (included), 4096 pressure levels
Processor / RAM Qualcomm octa-core / 6 GB RAM
Storage 64 GB internal, microSD slot
Frontlight Yes, warm + cool adjustable
Connectivity WiFi 6, Bluetooth 5.1, USB-C
Weight 420 g
Price (US) ~$499 with Pen2 Pro included

Strengths

Where the Boox Note Air 4 C review verdict earns the price

Three things separate the Note Air 4 C from every other color e-ink tablet at this price. First, app flexibility. Google Play installed by default means Kindle, Kobo, OneNote, Notion, library OverDrive, Adobe Reader, Anki, and most cloud-storage clients all install alongside the native note-taking app. No reMarkable or Kindle Scribe device offers this; it is the Boox moat. Our Boox Android apps guide covers the install paths and what works well on e-ink.

Second, color rendering. The Kaleido 3 panel renders more saturated color than reMarkable’s CANVAS or Amazon’s Colorsoft, both of which read more pastel. For users who want functional color (status coding in notes, color-aware PDFs, simple charts), Kaleido 3 fits better than the writing-first alternatives. Third, the writing experience has closed most of the latency gap with reMarkable; on the Note Air 4 C, paper-grade writing feel is genuinely close, not a marketing claim.

Tradeoffs

Where the Note Air 4 C falls short

Three trade-offs show up consistently in daily use. First, Android-on-e-ink is inconsistent. Apps designed for fast LCD refresh sometimes ghost or stutter on the Kaleido 3 panel even with Boox’s refresh-mode tuning. The native note-taking app and well-tuned readers (Kindle, Kobo) work cleanly; some productivity apps (Notion, certain Adobe workflows) feel sluggish. Test a free trial of any critical app before committing.

Second, the writing surface is glassier than reMarkable’s CANVAS. The latency is close but the friction-on-glass tactile feedback is not. For users coming from a paper notebook, the reMarkable feel is meaningfully better; for users coming from an iPad, the Boox feels like a step toward paper. Third, the do-everything posture means the device does not enforce focus the way reMarkable’s closed software does. Some buyers come to e-ink specifically to escape app distractions; Boox does not provide that escape.

Compared to

Boox Note Air 4 C review: how it compares to alternatives

The most useful comparisons are against three direct alternatives. Against the reMarkable Paper Pro at $579, the Note Air 4 C trades writing-feel polish for app flexibility and saves $80; our Paper Pro vs Boox piece covers the head-to-head. Against the Kindle Scribe Colorsoft at ~$629, the Note Air 4 C trades Kindle ecosystem integration for a more saturated color panel and Android flexibility; our Boox vs Kindle Scribe piece covers that decision.

Inside the Boox lineup, the choice is between the Note Air 4 C and the rumored Note Air 5 C successor. The 5 C is expected to upgrade to the Kaleido 4 panel; if you can wait, the next-gen device may be worth waiting for. Our Note Air 5 C launch hub tracks what is shipping in the successor.

Verdict

Should you buy the Boox Note Air 4 C in 2026

You are The right pick
An app-flexible user wanting color e-ink Note Air 4 C (this device)
A writing-first user without strong app needs reMarkable Paper Pro instead ($579)
A Kindle-heavy reader Kindle Scribe Colorsoft instead
A power user willing to wait for newer panel tech Hold for the Note Air 5 C launch
An on-budget Boox curious user Refurb Note Air 4 C from the official store

The honest summary: the Note Air 4 C is the right pick for users whose workflow specifically benefits from Android apps on color e-ink. For users who want the closed-software focus of reMarkable or the Amazon ecosystem of Kindle Scribe, the Note Air 4 C is the wrong answer at any price. Refurb units appear in the official Onyx store at meaningful discounts; our Boox refurbished guide covers the official store experience.

Bundle

If you have used the Boox Note Air 4 C for a few months, drop the verdict in the comments. Multi-month use surfaces the things review-week pieces never can, and this is where the long-form take stays current.