Finnish technology manufacturer Oura is facing a class action lawsuit in the United States alleging that the company exaggerated the accuracy of its smart ring sleep tracking features.
The legal action, first reported by tech publication TechCrunch, accuses the Finnish firm of misleading consumers regarding what its wearable health devices can actually measure.
Plaintiffs in the case contend that Oura smart rings are unable to directly determine sleep stages. According to the lawsuit, identifying distinct phases of sleep requires physiological data that can typically only be gathered in a laboratory setting.
The lawsuit asserts that Oura uses algorithmic estimates to calculate sleep patterns while advertising those figures to customers as precise measurements.
Allegations of misleading sleep data
Legal filings cite promotional materials in which Oura claimed a 79 percent accuracy rate for its device measurements. The lawsuit also highlights a subsequent statement from the company claiming 95 percent accuracy in determining sleep stages when measured against clinical laboratories.
In medical settings, clinical laboratories analyze sleep using specialized equipment to measure physiological signals such as brain activity, eye movements, and heart rates. Wearable devices worn on the finger rely instead on optical sensors and movement tracking to estimate when a user is resting.
According to lawsuit documents, prices for Oura rings start at approximately $300. The plaintiffs are asking the court to bar Oura from making allegedly deceptive accuracy claims and are seeking monetary compensation for buyers.
Oura had not provided a comment regarding the lawsuit at the time the report was published.
Company valuation and business expansion
Oura is a Finnish technology company that produces smart rings, which are lightweight wearable devices designed to track health metrics, physical activity, and sleep patterns continuously from a user's finger.
The class action suit arrives as the Finnish manufacturer seeks further commercial expansion, having previously submitted an application for an initial public offering. Investors valued the company at $11 billion in the autumn of 2025.
In addition to its public market plans, Oura has also filed a patent application for a smart ring featuring a replaceable battery, which would allow users to replace power components rather than purchasing an entirely new device.
