Review: Oura Ring 4

This year, more women than men wear the Oura ring—yes, that chunky finger nugget that is, or was, the health tracking tool for every Huberman-listening, MMA-fighting, raw-meat-eating tech bro. Fifty-nine percent of all Oura ring wearers are now women, and in particular, women in their twentiess, who have bought rings at 2.6 times the rate of other demographic groups.

I’m a woman, and I’ve worn an Oura ring consistently for several years now because it’s the only tool that can reliably predict my period. Many fitness trackers now have a temperature sensing feature that purportedly allows you to track that drop in basal body temperature (BBT) that accurately predicts your period, and that you used to only be able to measure with a thermometer under your tongue right when you get out of bed. However, in my testing, smart rings like the Oura are the only devices that that have consistently caught it.

With its new, rapidly expanding user demographic in mind, Oura has made a number of significant hardware and software changes to the fourth generation of the ring that make it a more convenient and wearable tool than ever. I also changed it up from the bro-y “Stealth Black” finish to the new brushed silver finish. It looks and feels more like jewelry than ever, and I like it.

No More Speed Bumps

The changes in the Oura Ring 4 acknowledged the big hurdle of wearing a smart ring, which is that we are tool-using mammals, we use our hands every day, and keeping a smart ring perfectly positioned for accurate data collection all the time is difficult. Previous generations of Oura rings had three clear plastic bumps for the photoplethysmogram (PPG) sensors that you were supposed to wear against the inside of your finger. You could feel the bumps and twist the ring so that it was positioned correctly.

The new ring doesn’t have any bumps. The sensors—which include red and infrared LEDs for blood oxygen; green and red LEDs for heart rate, heart rate variability, and sleep respiration; a digital temperature sensor; and an accelerometer—are recessed inside the body of the ring to make it thinner and more wearable. It also comes in a much bigger size range, with sizes from 4 to 15, although I again sized into my ring size 8.

The sensors are also now asymmetrically positioned to take measurements at a variety of tissue penetration depths, and Oura upgraded the number of signal pathways from 8 to 18. The Smart Sensing algorithm works with the sensors to continuously adapt to taking the best measurements at the best possible times, no matter what you happen to be doing with your hands. In practice, this means that the ring doesn’t have to be perfectly positioned all the time to take accurate measurements.

I tested the Oura in conjunction with the Garmin Fenix 8, one of the best premium sports watches, during a weekend at the river where my family and I engaged in a truly preposterous amount of (relatively low-key) physical activity. The Garmin auto-tracked three hikes during the day; the Oura auto-tracked 6, which was accurate. It also stayed on and tracked through a lot of soggy river scrambling, crawdad hunting, and rock throwing. Also, the Garmin also did not catch a night of insomnia, which the Oura Ring 4 did.

There’s a new charging dock, which is very attractive and charges the ring within an hour (even though it's not backwards compatible with the Gen 3). The battery life was also extended, which is true.

I get around three days of battery life with the Gen3. Right now, I am on the fourth day of wearing the Oura Ring 4 with, as I said, a pretty crazy amount of tracked physical activity through the weekend that included way too many hikes and a late-night outdoor music festival, and I still have what I would guess to be two to three more days of battery left. (I lead a pretty quiet life, but for some reason, whenever I test an Oura ring, I behave like an absolute maniac.)

Easy to See

Almost every fitness tracker’s app has undergone a redesign in the past year or so, but I like Oura’s more than most. The data is now organized into three tabs. Daily metrics like your activity goal and daytime stress are in the Today tab; you can click through more details in the Vitals tab; and measurements that are taken over time are shown in the My Health tab, like the new Cardiovascular Age feature that shows your overall heart health.

Unlike a wrist-based fitness tracker, you do have to check the app regularly on your phone instead of glancing at a morning report on a screen. I like that you don’t have to scroll through to check your most important metrics, which are lined up at the top of the new app like a little buffet of wellness. When you click through your in-depth measurements in Vitals, there’s another bar at the bottom that makes it easy to toggle between metrics as well.

A new feature called Timeline also allows you to add tags quickly and easily throughout the day, so you can spot unhealthy behavior patterns. Just tapping a button on the front page of the app is a much less tedious way of recording my activities than setting aside time to journal at the end of the day.

One feature in Timeline that I’m particularly excited about is Meals, which lets you upload pictures of your meals to the app for an AI analysis and to let you time your meals to align with your chronotype (I am a Late Morning person). My doctor has advised me to start eating more fiber, and finding out what foods have fiber in them is just a lot of work. This feature requires three to seven days to calibrate, and I haven’t gotten actionable advice yet. Meals is a feature within Oura Labs, the tab where you can try features that are still in development, and now it’s open to both iOS and Android users.

Like other temperature-tracking smart rings, Oura has also partnered with the fertility tracking app Natural Cycles to predict periods. While the testing period has not lined up with my time of the month, I have gotten an ovulation and prediction date that coincides with what the algorithm-based Clue app predicts.

The first rule of fitness trackers is that you should want to wear it, and be able to wear it for long periods of time. The new Oura Ring 4 appeals to a whole different demographic that might find wearing a basic Apple Watch to be … well, just a little nerdy and boring.

The ring is now smaller and lighter, it comes in much more stylish (and expensive!) new finishes, and without the bumps, it looks and feels a lot more like jewelry. It’s easier and more accurate to wear, and new software features are useful, actionable, and accessible. In a market segment that’s getting more and more crowded (Apple Ring, where are ye?), the Oura Ring 4 still stands out. And you’re not locked into a specific phone to use or wear it.