BOOX Note Air4 C

BOOX Note Air4 C

What the Note Air 4 C actually is

The Note Air 4 C sits in a specific slot in BOOX’s lineup: the flagship 10.3-inch colour note-taking tablet with EMR stylus. Not a pure reader like the Go 7 series. Not a pure monitor like the Mira Pro. Not the compact Go Color 7. This is the “one device that does everything” read books, annotate PDFs, sketch ideas, take handwritten notes, install any Android app in colour, at a screen size that fits an A4 page comfortably.

Two things separate it from cheaper BOOX tablets:

• Wacom EMR stylus (included in the box) rather than an active pen no battery, no charging, no lag, no risk of a dead pen when inspiration strikes
• Kaleido 3 colour display with an “improved” panel over the Note Air 3 C lighter background, faster refresh, better colour rendering

This isn’t the newest BOOX in this class (the Note Air 5 C was released in 2025 with Android 15), but the Note Air 4 C typically sits at a lower price point and covers the same core capabilities with essentially the same user experience.

The Kaleido 3 colour display the honest version

The 10.3″ Kaleido 3 display runs at dual resolution:

• Black-and-white content: 2,480 × 1,860 (300 PPI) — indistinguishable from a monochrome reader for text
• Colour content: 1,240 × 930 (150 PPI) — softer than an LCD, sharper than any older Kaleido generation

Two things to understand before buying:

Colours are muted, not vibrant. Kaleido 3 places a colour filter over a black-and-white E Ink panel. Reds look closer to a Sunday newspaper’s comics section than to a magazine cover; greens and blues are gentler. For PDF diagrams, syntax-highlighted code, colour-coded notes, textbook charts, and comic panels, it’s ideal. For photo editing, colour-critical illustration, or brand-accurate design work, it’s the wrong tool.

The screen is slightly darker than pure monochrome E Ink. The colour filter reduces overall white-area brightness. In dim rooms, this is more noticeable which is why the front light matters more than on monochrome tablets. In good ambient light, the difference is small.

BOOX’s “improved” Kaleido 3 panel on this model (vs the Note Air 3 C) is genuinely improved: lighter background colour, faster refresh, softer hue rendering. The generational bump is real.

Writing with the Pen Plus (EMR, included)

The BOOX Pen Plus ships in the box. It’s an EMR (electromagnetic resonance) stylus with 4,096 pressure levels, and understanding what EMR means matters here:

• No battery, ever. The tablet’s screen powers the pen via induction. You never charge it, never worry about it dying mid-meeting.
• Wacom-class accuracy. This is the same underlying technology that runs Wacom’s professional tablets and the reMarkable Paper Pro. Writing latency lands around 21 ms imperceptible for handwriting.
• Magnetic side attachment. The pen clips magnetically to the side of the tablet, so it stays with the device when you close the case.
• Tilt-sensitive. Genuine tilt for shading effects in sketch and drawing apps.

Compared to BOOX’s newer active-pen technology (InkSense on the Go Color 7 Gen II, InkSpire on the Tab X C), EMR is measurably better for fast writing and drawing no battery to charge, no lag, no risk of the pen sleeping when you pick it up. For anyone who writes seriously, EMR is the right technology, and it’s the reason the Note Air 4 C remains popular even as newer BOOX devices ship.

Android 13 with full Google Play Store

The Note Air 4 C runs Android 13 with unrestricted Google Play Store access. This is the biggest structural difference between BOOX and closed-ecosystem tablets like reMarkable or Kindle Scribe:

• Reading apps: Kindle, Kobo, Libby, Google Play Books, ComiXology (via Kindle), academic reader apps
• Note-taking apps: OneNote, Notion, Obsidian, Nebo, Squid, Google Keep
• Productivity: Word, Excel, PowerPoint, Google Docs, PDF Expert, Adobe Acrobat
• Cloud sync: Google Drive, Dropbox, OneDrive, iCloud web
• Communication: Slack, Teams, email clients

No BOOX-only ecosystem to buy into. Your existing library, your notes, your accounts everything works alongside BOOX’s native reader and note apps.

Performance and battery

Hardware Octa-core CPU (roughly 50% faster than the Note Air 3 C predecessor), 6 GB RAM, 64 GB internal storage plus microSD expansion. Fast enough for smooth multitasking across reading app, PDF annotation, and note-taking. Not iPad-fast, but genuinely responsive for e-ink standards.

Battery 3,700 mAh gives typical daily use (2–4 hours reading/writing with front light on) of 4–7 days between charges. Longer with lighter use. BSR (BOOX Super Refresh) draws more power than standard e-ink refresh, so battery life is shorter than a pure e-reader trading power for the improved refresh experience is a deliberate design choice. Fast USB-C charging brings the device to full in about 2 hours.

Full technical specifications

Supported file formats

• Documents: PDF, CAJ, DJVU, CBR, CBZ, DOC, DOCX, PPT, PPTX, TXT, RTF, HTML, CHM
• eBooks: EPUB, EPUB3, AZW3, MOBI, FB2, PRC
• Comics and manga: CBR, CBZ
• Academic and archive: DJVU, ZIP
• Images: PNG, JPG, BMP, TIFF
• Audio: WAV, MP3

What’s in the box

Contents vary by reseller — confirm at checkout.

Standard BOOX Store package:

• 1 × BOOX Note Air 4 C tablet
• 1 × BOOX Pen Plus stylus
• 1 × Magnetic folio cover
• 5 × Replacement stylus tips
• USB-C cable
• Card tray eject tool
• Quick start guide
• Warranty card

Amazon and some resellers:

• Tablet + Pen Plus only (folio and spare tips sold separately)

Check the specific bundle contents with your reseller before ordering the case and spare tips add real value if included, cost extra if not.

Who this device is for

Great fit:

• Note-takers who annotate PDFs and want colour highlighters
• Students studying colour textbooks, academic papers, medical/biology material
• Designers doing light sketching, wireframing, or brainstorming (not fine art)
• Manga and comic readers who want to annotate as they read
• Business users taking colour-coded meeting notes
• Anyone considering a reMarkable Paper Pro but wants full Android freedom
• Kindle Scribe users looking for colour + broader ecosystem

Not the right fit:

• Pure text readers — the monochrome Note Air 4 is $100 cheaper and has sharper text
• Photo editors or colour-critical designers — Kaleido colours are too muted
• Users who want the latest generation — the Note Air 5 C (2025) is the current model
• Anyone wanting a small pocket-sized device — 10.3″ is deliberately large

Note Air 4 C vs Note Air 5 C which to buy

BOOX released the Note Air 5 C in October 2025 as the successor. Differences:

• Note Air 5 C: Android 15, Pen 3 stylus, current-gen (2025+), typically $529
• Note Air 4 C: Android 13, Pen Plus stylus, 2024 release, typically $499

Practical differences are small — same 10.3″ Kaleido 3 display, same physical design, similar performance. Software support runway is longer on the 5 C (Android 15 will receive updates longer). For most users, if the price difference is small, the Note Air 5 C is worth it. If the Note Air 4 C is on meaningful clearance (below $450), it’s still an excellent buy the daily experience is essentially identical.

Note Air 4 C vs monochrome Note Air 4

BOOX also sells a monochrome Note Air 4 at roughly $100 less than the colour version. Trade-offs:

• Monochrome Note Air 4 wins on: text sharpness (no colour filter dimming), lower price, longer battery life
• Colour Note Air 4 C (this SKU) wins on: colour PDFs, colour-coded notes, comic/manga rendering, textbook diagrams

Match the model to what you actually read and write. If your work is 95%+ text, monochrome saves money without sacrificing capability. If colour matters even occasionally the Note Air 4 C’s added utility justifies the premium.