You’ve seen the ads, and honestly, the hype around smart rings is getting a bit loud. If you’re staring at your finger wondering if it’s time to switch from a bulky watch to a piece of jewelry, or if you’re already an Oura fan debating the upgrade, you’ve probably asked: Oura Ring 4 what does it do that’s actually different?
It’s not just a shinier version of the last one. Well, it is shinier, but the guts are where things got weirdly high-tech.
✨ Don't miss: Oconto County Measles Outbreak: What Really Happened and Why It’s Finally Over
Most people think a smart ring is just a step counter on your finger. It's not. The Oura Ring 4 is basically a tiny, titanium-wrapped computer that spends 24 hours a day whispering to an app about how stressed you are and why you shouldn't have had that late-night taco.
The "Smart Sensing" Secret
The biggest thing the Oura Ring 4 does differently than its predecessor is how it actually "sees" your blood. With the older Gen 3, you had those three little plastic bumps on the inside. They were... fine. But if the ring slipped or rotated while you were sleeping, the sensors lost their "view" of your veins, and you’d wake up to gaps in your data.
Basically, the Oura Ring 4 fixed this by ditching the bumps.
Instead of three paths for light to travel, it now has 18 signal pathways. This is what they call "Smart Sensing." Because the sensors are now recessed and flat against the titanium, the ring can dynamically switch between these 18 paths. If one side of the ring loses contact, it just shifts the workload to another sensor.
It’s the difference between trying to see through a keyhole versus a floor-to-ceiling window.
It Tracks Your Heart Without Being Annoying
Most of us are used to the green light on the back of a smartwatch flashing like a rave when we move our arms. The Oura Ring 4 handles this way more subtly.
It uses a mix of green, red, and infrared LEDs.
- Green handles your daytime heart rate and workout tracking.
- Infrared takes over at night because it's less intrusive and better for resting metrics.
- Red measures your blood oxygen (SpO2) while you’re knocked out.
Honestly, the accuracy jump is pretty wild. Data shows a 120% improvement in signal quality for blood oxygen sensing compared to the Gen 3. That means it’s much better at catching "breathing disturbances"—which is a polite way of saying it knows when you’re snoring or struggling for air.
What Actually Happens in the App?
The ring doesn't have a screen, so you're going to spend a lot of time in the Oura app. They recently redesigned it to be less of a data dump and more of a "daily vibe check." You get three main scores: Readiness, Sleep, and Activity.
- Readiness Score: This is the big one. It looks at your body temperature, resting heart rate, and HRV (heart rate variability). If you stayed up too late or you're starting to get a cold, this score will tank. It’s basically the ring telling you to "take it easy today, champ."
- Sleep Score: It breaks down your REM, deep, and light sleep. The Oura Ring 4 is actually 90.6% accurate for REM sleep when compared to a medical-grade sleep study. That’s better than almost any wrist-based wearable out there.
- Activity Score: This is where the ring used to be "kinda okay" but is now much better. It automatically detects over 40 types of activities. You don't have to tell it you're walking the dog; it just knows. It even gives you heart rate zones for your workouts now.
The Women’s Health Component
One of the most powerful things the Oura Ring 4 does is track body temperature trends. For women, this is huge. It doesn't just guess when your period is coming; it looks for the actual temperature shift that happens during ovulation. It integrates with apps like Natural Cycles (which is FDA-cleared) to help with birth control or pregnancy planning.
Design: Titanium and Ceramic
They finally went all-in on materials. The Oura Ring 4 is fully titanium—inside and out. The Gen 3 had a plastic (epoxy) inner lining, which felt a bit cheap if we’re being real. The new one feels like a piece of high-end jewelry.
They also added a Ceramic variant in 2025. It comes in colors like "Midnight" and "Tide." The cool thing about the ceramic is that the color is baked into the material, not just a coating. So if you scratch it, you aren't going to see silver poking through.
A quick heads-up on sizing: The Ring 4 fits a bit differently because the sensors are flat. If you’re coming from a Gen 3, don’t just order the same size. Get the new sizing kit. It covers sizes 4 through 15 now, which is great for people with smaller or larger hands.
✨ Don't miss: Exactly how many grams of protein in an ounce of chicken: The truth about your macros
The Battery Reality
Oura says the battery lasts up to 8 days.
In the real world? It depends. If you're tracking three workouts a day and have every notification turned on, you're looking at more like 5 or 6 days. Still, that’s way better than an Apple Watch that dies before you finish your morning coffee.
The charger is redesigned too. It’s a sleek aluminum puck that stays put on your nightstand. It takes about 20 to 80 minutes to juice up. Most people just drop it on the charger while they shower, and they never have to think about it again.
Is the Subscription Worth It?
Here’s the part people hate: the subscription.
The ring costs between $349 and $499 depending on the finish. But to see your actual data trends and get the "scores," you have to pay $5.99 a month.
Without the subscription, you basically just get your basic scores for the day. No long-term trends, no deep sleep analysis, no "Oura Advisor" AI coaching. It’s a bummer, but that’s the business model everyone is moving toward. Samsung’s Galaxy Ring doesn’t have a fee yet, so that’s the main competition if you’re "subscription-allergic."
Who Is This Actually For?
The Oura Ring 4 isn't for the hardcore marathon runner who needs to see their pace in real-time on their wrist. It’s for the person who wants to understand their health without looking like they're wearing a mini-computer.
It's for the person who cares about:
- Recovery: Knowing when to push and when to nap.
- Discretion: It looks like a wedding band, not a gadget.
- Sleep Quality: Getting the most accurate data possible while they're unconscious.
If you’re someone who gets "notification fatigue" from a smartwatch buzzing every five seconds, this is a breath of fresh air. It just sits there, does its job, and gives you a report in the morning.
Moving Forward With Your Health
If you're ready to pull the trigger, your first step isn't actually buying the ring—it's ordering the sizing kit. Because the sensors are recessed, the fit needs to be snug but not "cutting off circulation" tight. Wear the plastic sizer for at least 24 hours, because your fingers swell at night and after you eat salty food.
📖 Related: How to Tell Your Mom You Got Your Period Without It Being Super Awkward
Once you have your size, pick a finish that matches your daily style. If you lift heavy weights, the Stealth (matte) finish is legendary for its durability, but the Ceramic options are arguably the most stylish. Just remember to sync it every morning to see how yesterday's choices are affecting today's energy.