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Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →The BOOX Note Air4 C is a slim 10.3-inch color e-paper reader that adds handwriting tools and Android app access. Android Central reviewer Namerah Saud Fatmi reported two to three weeks of battery life, but the review did not compare it with the Galaxy S25 Ultra under controlled, matching conditions. The result is a capable reading and note-taking device—not a demonstrated battery-life winner over that phone.
What the Note Air4 C is—and what it is not
The Note Air4 C combines a color e-paper screen with a stylus, note-taking software and Android 13. BOOX lists it for reading and writing; its official store describes it as a color ePaper notebook for creators and thinkers, including use in meetings and lectures. That is the manufacturer’s positioning, while the day-to-day assessment below comes from Android Central’s review.
It is best understood as an e-reader and digital notebook that can also run Android apps. Fatmi found it useful for light-to-moderate school or office work, but noted it does not feel as snappy as a conventional Android tablet. If your priority is fast general-purpose tablet performance, e-paper’s reading and writing strengths may not compensate for that trade-off.
Specifications and display
BOOX’s Help Center lists these specifications. They are manufacturer-provided figures, not independent measurements.
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#1 Best Overall
- Screen: 10.3" Kaleido 3 (4,096 colors) glass screen with flat cover-lens. Resolution: B/W: 2480 x 1860 (300 ppi). Color: 1240 x 930 (150 ppi). Touch: BOOX stylus with magnetic type + capacitive touch. CPU: Qualcomm 6690 + BSR GPU. RAM: 6GB. ROM: 64GB. Connectivity: Wi-Fi + BT 6.0. Front Light with CTM (Warm and Cold)
- OS: Android 16. Document Formats: PDF, CAJ, DJVU, CBR, CBZ, EPUB, EPUB3, AZW3, MOBI, TXT, DOC, DOCX, FB2, CHM, RTF, HTML, ZIP, PRC, PPT, PPTX. Image Formats: PNG, JPG, BMP, TIFF, GIF. Audio Formats: WAV, MP3 Supports 3rd-party apps
- Button: Power Button with Fingerprint Recognition USB-C Port (Supports OTG or use as an audio jack) microSD Card Slot Built-in Dual Speakers Built-in Microphone. Battery: 3,700mAh Li-ion Polymer. Battery Dimensions: 225 x 192 x 5.8 mm (8.9" x 7.6" x 0.23") Weight: Approx. 440 g (15.5 oz)
| Specification | BOOX-listed value |
|---|---|
| Screen | 10.3-inch Kaleido 3 color e-paper |
| Black-and-white resolution | 2480 × 1860, 300 ppi |
| Color resolution | 1240 × 930, 150 ppi |
| Processor | Octa-core CPU |
| Memory and storage | 6GB RAM; 64GB storage |
| Operating system | Android 13 |
| Stylus | BOOX Pen Plus |
| Battery | 3700mAh |
| Connectivity | USB-C with OTG |
| Dimensions | 226 × 193 × 5.8mm |
| Weight | Approximately 420g, according to BOOX |
The lower color resolution is a key distinction: color content is rendered at 150 ppi, compared with 300 ppi for black-and-white content. That makes the device suited to color accents, diagrams and illustrated reading, rather than a high-resolution color tablet experience. The review separately reports a weight of 430g, a microSD slot and 15W wired charging; the weight differs from BOOX’s listed approximate 420g, so the figures should not be treated as a single verified measurement.
Reading, handwriting and Android apps
Reading and annotation
The e-paper panel is the central reason to choose this device. It supports ordinary reading alongside handwritten annotations, and the review praised reduced ghosting compared with the predecessor. Ghosting and display performance are reviewer observations, not standardized test results, so readers should weigh them as practical impressions rather than laboratory measurements.
Rank #2
- Dark, gray, or wrongfully believed low resolution screen : All Eink products used Kaleido 3 color e-ink technology, which currently has inherent limitations and share the same darker or grayer screen than LCD/LED ones. This is a characteristic of all e-ink products, not a defect. If it doesn't meet your expectations, you may return the product under our return policy. However, please note this is not considered a product fault.
- Over 99% of mobile apps are optimized for LCD/OLED screens with: High refresh rate expectations; Color-rich interfaces; Animation-heavy designs; These design choices conflict with E Ink's natural strengths in static content display.Energy Efficiency Trade-off: E Ink relies on electrophoretic particles that physically move to form images, resulting in slower refresh rates, makes it inherently unsuitable for conventional app interfaces designed for always-powered displays. If the buyers are not satisfied, they can apply for return or exchange, but it cannot be regarded as a malfunction.
- Wrongfully believed dead pixels: for B/W spots on the screen, if their diameter does not exceed 0.5mm, they are all regarded as normal. All E - INK products comply with this industry standard. If the buyers are not satisfied, they can apply for return or exchange, but it cannot be regarded as a malfunction.
- Performance (Freezes up): E-ink technology utilizes electrophoretic ink, which inherently has a lower refresh rate compared to LCD/OLED tablets. Customers who accustomed to high-speed smartphones may perceive this natural latency as "freezing." This is a characteristic of the eye-friendly technology, not a system failure.
Handwritten notes
Android Central highlighted native handwriting OCR, which can turn handwriting into searchable or usable text, as a strength. That makes lecture notes, meeting notes and marked-up documents a more natural fit than they would be on a basic e-reader.
Android flexibility
The device provides access to Google Play, so readers can install Android apps rather than relying only on a closed e-reader storefront. The benefit is flexibility; the limitation is that an e-paper display and its interaction speed do not make every app feel like it would on a conventional tablet.
Rank #3
- Screen: 10.3" Kaleido 3 (4,096 colors) glass screen with flat cover-lens. Resolution: B/W: 2480 x 1860 (300 ppi). Color: 1240 x 930 (150 ppi). Touch: BOOX stylus touch (4,096 levels of pressure sensitivity) + capacitive touch. CPU: Octa-core + BSR RAM: 6GB ROM: 64GB Connectivity: Wi-Fi + BT 5.1 Front Light with CTM (Warm and Cold) G-sensor for Auto Rotation
- OS: Android 15 Document Formats: PDF, CAJ, DJVU, CBR, CBZ, EPUB, EPUB3, AZW3, MOBI, TXT, DOC, DOCX, FB2, CHM, RTF, HTML, ZIP, PRC, PPT, PPTX Image Formats: PNG, JPG, BMP, TIFF Audio Formats: WAV, MP3 Supports 3rd-party apps
- Button: Power Button with Fingerprint Recognition USB-C Port (Supports OTG or use as an audio jack) microSD Card Slot Built-in Dual Speakers Built-in Microphone Battery: 3,700mAh Li-ion Polymer Dimensions: 225 x 192 x 5.8 mm (8.9" x 7.6" x 0.23") Weight: Approx. 430 g (15.2 oz)
- Dark, gray, or wrongfully believed low resolution screen : All Eink products used Kaleido 3 color e-ink technology, which currently has inherent limitations and share the same darker or grayer screen than LCD/LED ones. This is a characteristic of all e-ink products, not a defect. If it doesn't meet your expectations, you may return the product under our return policy. However, please note this is not considered a product fault.
- Over 99% of mobile apps are optimized for LCD/OLED screens with: High refresh rate expectations; Color-rich interfaces; Animation-heavy designs; These design choices conflict with E Ink's natural strengths in static content display.Energy Efficiency Trade-off: E Ink relies on electrophoretic particles that physically move to form images, resulting in slower refresh rates, makes it inherently unsuitable for conventional app interfaces designed for always-powered displays. If the buyers are not satisfied, they can apply for return or exchange, but it cannot be regarded as a malfunction.
How to interpret the battery-life claim
Android Central’s 2025 review reports that Fatmi experienced two to three weeks of battery life. It does not specify a standardized test protocol, daily usage hours, brightness or refresh settings, or a matching Galaxy S25 Ultra test. Treat the figure as one reviewer’s experience, not a guaranteed runtime for every owner.
BOOX lists a 3700mAh battery, but capacity alone does not establish how long a device lasts in a particular use pattern. E-paper reading, note-taking, app use and display settings can differ substantially from one owner to another. The review’s “better battery life” framing versus the S25 Ultra is therefore a characterization, not a controlled apples-to-apples comparison.
Rank #4
Build, portability and purchase caveats
At a listed thickness of 5.8mm, the Note Air4 C is exceptionally thin on paper. The review says it has no ingress protection, so it should not be treated as water- or dust-resistant. Android Central also reports that the dedicated cover is sold separately, adding a separate accessory purchase for readers who want a cover.
The review said the device shipped with Android 13 and that BOOX promised at least three years of firmware updates. That is the promise reported in the 2025 review; it does not establish the current support status or remaining update period.
Best Value
Is the Note Air4 C worth choosing over the Note Air 3 C?
Android Central’s review asks whether the newer model’s upgrades justify its premium over the Note Air 3 C. The reviewer describes the older device as a cheaper alternative at the time of publication, while praising the Air4 C’s performance improvement, handwriting OCR and reduced ghosting. Whether those differences warrant paying more depends on how much you value those improvements; the review’s price comparison is historical, not a current price recommendation.
Before choosing either model, compare the current prices and availability, the cost of a compatible cover, and whether the older device already meets your reading and note-taking needs. Also consider that the Air4 C’s Android flexibility does not remove the responsiveness limits of e-paper. Current prices, successor models and software support can change, so the review alone cannot establish which model is the best buy today.
Who should consider it?
- Good fit: Readers who want color e-paper, stylus notes, handwriting OCR and Android app access in one device.
- Potential fit: Students and office users doing reading, annotation and light-to-moderate work, as characterized in Android Central’s review.
- Less suitable: Buyers who need a fast general-purpose tablet, a water-resistant device, or a proven battery-runtime advantage over the Galaxy S25 Ultra.
Android Central’s review calls it “a spectacular e-reader that doubles as an e-note as well as an Android tablet for light to moderate office and school work.” That is the publication’s editorial verdict, not a manufacturer claim.
Quick Recap
Sources
- Namerah Saud Fatmi, Android Central review, published February 1, 2025.
- BOOX Help Center specifications for the Note Air4 C.
- BOOX official store product page.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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