Onyx Boox Note Air 5c vs 4c: Is It Worth the Upgrade?

The Onyx Boox Note Air 5c vs 4c debate is one I get asked about constantly, and it is easy to see why. Both devices look nearly identical. Same size, same color e-ink display, same general form factor. If you placed them side by side, you might struggle to tell them apart at a glance. But spend time with both — as I have — and a clear picture emerges about who should upgrade and who should hold off.

Think of it this way: the 4c is like a capable older sibling. Still strong, still relevant, still gets the job done. The 5c is the younger one who just came home from college — a little more mature, wearing newer clothes, carrying upgraded skills. Same family DNA, but the 5c has leveled up in ways that matter for serious digital planners and note-takers.

In this guide I am going to break down exactly what changed, what stayed the same, and give you a straight answer on whether the upgrade makes sense for your workflow — especially if you are using something like the Key2Success digital planning system as your daily driver.

Same Family, Different Generation

When Onyx Boox released the Note Air 5c, they were not reinventing the wheel. They were refining it. The 4c was already a strong device — solid color e-ink display, open Android ecosystem, good stylus performance, and genuine utility as a daily planning and note-taking tool. The 5c does not throw any of that away. It builds on it.

What you get with the 5c is a generational step rather than a generational leap. The screen technology is the same. The physical dimensions are essentially identical. The battery performance is comparable. This is important context because it means if you are currently using the 4c and it is meeting your needs, you are not working with an outdated device. The 5c just removes some friction points that, once you experience their absence, you will not want to go back to.

For those coming to the e-ink device market fresh — with no existing Boox hardware — the decision is straightforward. The 5c is the right choice at current pricing. The gap between the two in terms of feature set versus cost makes the 5c the better investment for anyone buying new in 2026.

What Actually Changed: The 5c Upgrades That Count

Not all spec bumps are created equal. Some upgrades look impressive on paper but make no real difference to how you use a device day to day. The 5c improvements are different — they address actual pain points that Boox users have flagged over time. Here is what changed and why it matters.

Android 15 vs Android 13

The 5c ships with Android 15 compared to Android 13 on the 4c. For most casual users, an OS version number does not sound exciting. For productivity app users, it is genuinely significant. Android 15 brings better compatibility with newer app versions moving forward, which means apps like OneNote for cross-device planning and annotation tools will continue to receive updates and function reliably for longer. The software support lifecycle on the 5c simply extends further into the future, meaning your hardware investment stays relevant longer.

You also get improved security with Android 15 — relevant if you are using your Boox device for work note-taking, client meetings, or storing sensitive planning data.

Keyboard Cover Connector

The 5c introduces a new pin connector that supports a keyboard cover accessory — something that was never available for the 4c. This turns the 5c into more of a workspace or laptop-adjacent experience when you want it. For planners who occasionally need to type longer notes, draft content, or work in a more traditional document-editing mode, this adds genuine versatility that the 4c simply cannot match.

Faster Fingerprint Reader

A small but noticeable improvement — the fingerprint sensor on the 5c responds noticeably faster than on the 4c. If you unlock your device frequently throughout the day, this adds up. It keeps you in flow rather than adding a small moment of friction every time you pick up the device.

The New Stylus Is the Biggest Win

If there is one upgrade on the 5c that makes the biggest immediate difference, it is the pen. And specifically, it is one feature that sounds almost trivial until the moment you need it: built-in nib storage inside the stylus itself.

Here is the scenario that sold me on this. You are heading into one of the most important meetings of the quarter. Maybe a major sales call, a client review, a board presentation. You reach for your stylus and the nib is gone — snapped off when you dropped it last week, or worn down to nothing over months of heavy use. You now have a beautiful e-ink device and no effective way to write on it. That has happened to me. It has happened to a lot of Boox users.

With the 5c stylus, you never face that problem. Extra nibs are stored directly inside the pen itself. Pull one out, swap it in, keep writing. Never miss a note, never miss a beat. It sounds simple because it is — and that simplicity is exactly why it works so well in practice.

Beyond the nib storage, the pressure sensitivity and overall writing feel of the 5c stylus is noticeably improved. The lag between stylus contact and ink appearing on screen — something that has been a mild complaint on e-ink devices in general — is reduced on the 5c. Real-time note rendering feels more immediate, which matters when you are writing quickly in a meeting or trying to capture fast-moving thoughts in your daily planning session.

What Stayed the Same

Knowing what did not change is just as useful as knowing what did — especially if you are a 4c owner trying to decide whether to upgrade. Here is an honest accounting of what Onyx Boox kept consistent between the two devices.

The bottom line: if you are using the 4c primarily for reading and occasional handwriting, and those core functions are working well for you, the 5c does not represent a dramatic difference in your day-to-day experience. But if you write heavily, take notes in meetings, use productivity apps, or want a device that stays supported for the next several years — those 5c upgrades add up to a meaningful improvement.

So Which One Should You Buy?

Here is the straightforward answer, because you deserve one rather than a hedged non-answer.

Buy the 5c if: You are purchasing new, you write heavily in meetings or planning sessions, you rely on apps like OneNote or GoodNotes for iPad-connected planning workflows, or you want a device that will stay fully supported and compatible with modern apps for the next several years. The Android 15 upgrade, the new pen, and the keyboard cover connector collectively make the 5c the better value at comparable price points.

Stick with the 4c if: You already own one and it is meeting your needs. The 4c still delivers that paper-like e-ink writing experience, still runs Android with access to the Play Store, and still supports PDF-based planners like the Key2Success Planner editions without issue. If budget is the deciding factor and you are choosing between a new 4c and a new 5c, lean toward the 5c — but if you are choosing between keeping your existing 4c versus spending money on the 5c, there is no urgency to upgrade right now.

The most important thing either way is that you are actually using a system. The device is only as valuable as the planning habits you bring to it. A 4c with a consistent daily planning practice will produce better results than a 5c sitting on a shelf.

Frequently Asked Questions About the Onyx Boox Note Air 5c vs 4c