Smart rings from brands like COLMI have become one of the most searched wearables on AliExpress, almost always in the same breath as Oura — the $300-plus ring most people are actually trying to find a cheaper way into. The comparison holds up better in some places than others.
In this guide
Why the Oura comparison keeps coming up
Oura popularized the smart ring category and set the price expectation most buyers now compare everything else against — a few hundred dollars for the ring, plus an ongoing membership to see most of what it tracks. AliExpress smart rings, COLMI's lineup especially, aim at the same core feature set (heart rate, sleep, activity, sometimes SpO2 and skin temperature) at a fraction of the upfront cost and with no subscription at all. That's the appeal in one sentence — the question worth actually answering is how much gets lost getting there.
Accuracy — where it holds up, where it doesn't
Heart rate and basic step tracking tend to be reasonably close to premium rings for day-to-day trend-watching — not clinical-grade, but close enough to notice a genuinely bad night's sleep or a harder-than-usual workout. Where the gap tends to widen is in the more processed metrics: sleep stage breakdown (light vs deep vs REM specifically, not just total sleep time) and heart rate variability are both harder to get right and where budget rings are more likely to diverge from what a premium ring reports. If you need precise clinical data, this category isn't that. If you want a rough, consistent daily trend to notice changes over time, it's generally good enough for that.
Sizing is the step people skip
This is the single most common way a smart ring purchase goes wrong, and it has nothing to do with the electronics. A smart ring needs to fit snugger against skin than a normal jewelry ring for its sensors to read accurately, and finger size genuinely shifts with temperature, time of day, and swelling — a size that feels right on a cold evening can be tight by afternoon. Look for a seller offering a separate, cheap sizing kit (a set of plastic rings you wear for a full day before ordering the real thing) rather than guessing from a standard ring size chart. Skipping this step is the most common reason people end up with a ring that's uncomfortable or reads inconsistent data.
No subscription is the real advantage
This is worth stating plainly since it's the actual structural difference, not just a price gap: Oura requires an ongoing membership to unlock most of its insights after an initial trial period, while COLMI and most other AliExpress smart ring brands give full access to their app's tracking data with no recurring fee at all. The trade-off is real too — the app experience is generally less polished, insights are more raw data than curated coaching, and long-term software support varies a lot by brand. For someone who mainly wants the raw numbers without paying monthly for the privilege, that trade is often worth it.
What to check before buying
Beyond sizing, a few things matter more for smart rings than most product categories: battery life claims (several days is typical; treat multi-week claims skeptically), whether a charging dock is included or sold separately, stated water resistance if you plan to wear it in the shower or swimming, and app compatibility with your specific phone. Reviews mentioning the app after weeks of real use — not just the unboxing — are worth more here than almost anywhere else on this site, since the software is as much the product as the ring itself.
Frequently asked questions
Are AliExpress smart rings as accurate as an Oura Ring?
Close on the basics, less consistent on the details. Heart rate and step counting tend to track reasonably well against premium rings, but sleep staging (distinguishing light, deep, and REM specifically) and HRV tend to be where the gap shows up most. For a rough daily trend rather than clinical-grade precision, most buyers find it good enough.
How do you get the right size for a smart ring?
Order a sizing kit before the actual ring if the seller offers one — a set of cheap plastic rings you wear for a day to find your true size, since finger size shifts with temperature and time of day. Buying based on a normal jewelry ring size alone is a common mistake, since a smart ring needs to sit snugger against skin for its sensors to read accurately.
Do AliExpress smart rings require a subscription like Oura?
Generally no, and this is the single biggest practical difference. Most AliExpress smart ring brands, COLMI included, give full access to their app's tracking data with no recurring fee, whereas Oura requires an ongoing membership to see most of its insights after the first month. The trade-off is usually a less polished app experience in exchange for not paying monthly.
