If you’ve ever looked at your toothbrush and thought, “Am I doing enough?”, you’re not alone. With all the buzz around oral care tech these days, it’s easy to feel like your manual brush just isn’t cutting it anymore. And let’s be honest: brushing your teeth is one of the most repeated routines in your life, so it makes sense to want a tool that’s up to the task.
That’s where Oral-B’s iO series comes in. Sleek, modern, and full of smart features, these brushes are designed to turn a basic chore into something a little more intentional. But even within the iO line, not all brushes are created equal — especially when you’re trying to choose between the Oral-B iO 3 and the iO 4.
They’re both entry-level. Both promise a powerful clean. But the question is: which one gives you more where it counts? We’ve taken both for a spin, and here’s how they really compare.
Design and ergonomics: same shape, different shades
From the outside, you’d be forgiven for mixing them up. Both the iO 3 and iO 4 share the same ergonomic silhouette, with that signature matte finish, minimalist interface, and one-button control. Dimensions are identical, and they sit just as comfortably in the hand whether you’re brushing in the morning rush or winding down at night.
Where they do diverge slightly is in style. The iO 3 comes in black, blue, and pink, while the iO 4 is available in black, white, and lavender. Subtle? Sure. But if you’re picky about your bathroom color palette — or just love a lavender brush — it’s something to consider.
Both models skip the flashy digital displays found in the higher iO numbers, keeping things visually simple. And for many, that’s a plus: you get the sleek look without the added complexity.
Brushing modes: the one extra that makes a difference
This is where the first real distinction comes into play. The iO 3 gives you three modes: daily clean, sensitive, and whitening. All solid, all useful.
But the iO 4 adds a fourth one: gum care. It might sound like a small thing, but if you’ve ever dealt with irritation, bleeding, or just want to treat your gums a little more gently — that extra mode is more than welcome.
So yes, the iO 4 adds just one more setting, but it opens up a new brushing experience. Not everyone will use it daily, but when your gums feel sore or inflamed? It’s a game changer.
Smart features: Bluetooth makes a real impact
Here’s the big one. The Oral-B iO 4 comes with Bluetooth. The iO 3 doesn’t. And honestly, that’s the upgrade that makes the 4 feel like a step into the smart toothbrush space.
With Bluetooth, you can connect your brush to the Oral-B app, and suddenly you’ve got access to real-time feedback, brushing stats, guidance, and even reminders. Want to know if you’re brushing long enough? The app tracks that. Wondering if you’re missing areas? It tells you.
The iO 3, by contrast, works alone. It still vibrates to let you know when it’s time to switch quadrants, and it still gives you feedback through light and motion — but that’s it. No syncing, no personalized coaching, no progress tracking.
If you’re someone who likes data, habits, and improvement, the iO 4’s app integration makes the routine feel more meaningful. And that kind of motivation goes a long way when trying to build consistent habits.
Cleaning experience: equal where it counts
Now here’s the good news for both camps: when it comes to actual brushing performance, these two are identical.
Both models use the same oscillating-rotating movement with microvibrations, the signature feature of the iO line. That means you’re getting the same deep-clean technology that made the higher-end iO brushes popular in the first place.
They also share the same smart pressure sensor, which lights up if you’re brushing too hard. It’s subtle, but effective — and a great way to avoid enamel damage or gum irritation without even thinking about it.
So while one brush may have more bells and whistles, they both deliver the same core clean, and that’s important to keep in mind if performance is your top priority.
Battery life and charging: identical endurance
This part’s easy. Both the iO 3 and iO 4 offer up to 14 days of battery life on a full charge, depending on how often and how long you brush. That’s enough for everyday use and most trips — no anxiety about running out mid-weekend.
Charging time sits at around 16 hours for both, which isn’t blazing fast, but it’s reliable. Plug it in overnight and you’re good to go for two weeks.
The magnetic charger is compact and stable, and the brush clicks on with a satisfying snap. So if you’re wondering whether one will save you more time at the plug, the answer is: they’re neck and neck.
Travel and accessories: a useful little bonus
Here’s another small but surprisingly impactful difference: the iO 4 comes with a travel case. The iO 3 does not.
Now, you might be thinking — “Does that really matter?” But if you’ve ever tossed your brush in a suitcase or gym bag and watched the bristles get flattened or gunky, you already know the answer.
That travel case gives the iO 4 just a bit more practicality for real-life use. Whether you’re heading on a weekend trip or just want to keep the brush clean in a drawer, it adds convenience without taking up extra space.
Both models include one brush head and the standard charger. So this isn’t about quantity, but about small thoughtful details that make daily life easier.
Feature simplicity vs feature depth
At the end of the day, the iO 3 is all about essential function. It’s for people who just want to brush effectively, with a great motor, a smart sensor, and a bit of whitening thrown in. No apps, no setup, no extras. Just plug it in and go.
The iO 4 is a step deeper. It keeps the same core cleaning engine, but adds more customization, more guidance, and more flexibility. From the extra gum care mode to the Bluetooth app connection, it gives you tools that grow with you — and might even help you improve your routine over time.
And it’s not just about the tech. It feels like a brush that’s built for a smarter lifestyle, especially for those who like tracking health data or just want a little feedback without going full high-end.
Build quality and compatibility: the iO promise holds up
Here’s a quick one: both brushes are built to last. Solid construction, excellent water resistance, responsive buttons, and that satisfying weight that makes them feel premium even without the screens or flashy features of the iO 6 or iO 9.
And thankfully, both are fully compatible with any of the Oral-B iO brush heads, so you’re free to choose deep cleaning, sensitive, whitening, or whatever fits your needs. That kind of flexibility is underrated, and it means you won’t outgrow your brush just because your needs change.
Final call: iO 4 brings more to the table
After going through every detail — features, design, performance, extras — it’s hard to deny that the Oral-B iO 4 is simply the more complete brush.
It gives you more modes, more customization, more data, and more flexibility. The Bluetooth feature may seem minor at first, but once you use the app for a week, it changes how you approach brushing. Add the travel case, and it starts to feel like a smarter, more adaptable tool for daily hygiene.
That said, the iO 3 isn’t a downgrade in terms of cleaning. If you want a no-frills brush that does its job exceptionally well, with no setup and no app notifications, the iO 3 is solid — and for many, it’s all you need.
But if you’re the type of person who wants just a bit more — more insight, more personalization, more readiness for travel — then the iO 4 is the one to go for. It’s the smarter choice without jumping into premium price territory.
Because sometimes it’s not about what’s essential — it’s about what makes daily habits easier to stick with. And the iO 4? It gets that.