People who bought an Oura Ring 4, Ring 4 Ceramic or Ring 5 may be covered by a proposed class action alleging Oura overstated how accurately the rings track sleep stages, including a claim of “95% Sleep Staging Accuracy.” Oura disputes the allegations. No class has been certified and there is nothing to file yet.
Allegations Only · No Settlement Yet
This article describes a class action complaint. The statements below are unproven allegations. Oura Inc. and Oura Health Oy have not been found liable, there is no certified class, and nothing to claim at this time. This page is informational and is not legal advice.
What Is This About?
A Los Angeles County woman who bought an Oura Ring 4 filed a proposed class action against Oura Inc. and its Finnish parent, Oura Health Oy, on August 20, 2026 in the U.S. District Court for the Northern District of California. The case is Surber v. Oura Inc., No. 3:26-cv-08686.The complaint says Oura sold its rings, priced from about $300, as able to track the four stages of sleep (wake, light, deep and REM) with near-clinical accuracy. It argues that a ring worn on the finger cannot do that, because sleep stages are defined by brain waves, eye movements and muscle tone that only a laboratory sleep study, known as polysomnography, measures directly.
Oura disputes the claims. In a statement reported by TechCrunch, the company said it stands behind its “science, research, and accuracy claims” and will defend against the allegations. None of the claims have been proven.
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The Accuracy Claims Being Challenged
The complaint quotes Oura’s website and advertising, including statements that the rings are:- “Built for accuracy” and offer “Unparalleled Accuracy”
- At “79% agreement with gold-standard polysomnography (PSG)” for classifying the four stages of sleep
- Capable of “95% Sleep Staging Accuracy compared to clinical sleep lab,” the most recent version of the claim
- “An Alternative to PSG Sleep Studies,” a phrase the complaint traces to an Oura blog post
The Research the Complaint Cites
The complaint says Oura’s accuracy figures come from studies the company funded, and points to independent research with lower numbers. Its main example is a March 2025 study in Scientific Reports, a Nature Portfolio journal, that tracked 45 nights of sleep. According to the complaint, the study found the Oura ring correctly classified sleep stages 53.18% of the time, overestimated REM sleep by more than 31 minutes, and underestimated light and deep sleep.The complaint also cites a 2026 study in Sleep Advances by University of Massachusetts researchers, which it says found significant differences between Oura readings and laboratory sleep studies, especially in older adults. Oura says its algorithm was developed using more than 1,200 nights of data, according to MedCity News, and has published blog posts defending its methods.
Who Is in the Proposed Class?
The complaint proposes a nationwide class of everyone who bought the rings in the United States, for purposes other than resale, within the applicable limitations periods. It also proposes a California subclass of buyers in the state during the four years before the case was filed.The claims include fraud by misrepresentation, unjust enrichment, California’s Unfair Competition Law, False Advertising Law and Consumers Legal Remedies Act, breach of express warranty, and breach of implied warranty under California’s Song-Beverly Act. The complaint asks the court to stop the challenged advertising and to award restitution of the price premium buyers paid, along with damages.
What Happens Next?
Oura has said it will defend the case. The court has not ruled on whether the claims can go forward, and there is no settlement, certified class or claim form. A separate, earlier Oura case over membership auto-renewals is listed on OCA’s auto-renewal class actions page.Questions
Which Oura rings are in the lawsuit?
The complaint names the Oura Ring 5, Oura Ring 4 and Oura Ring 4 Ceramic, and says it covers every version of the Oura Ring sold in the United States, in any size, color or material.
What accuracy claims does the lawsuit challenge?
The complaint points to statements that the rings are “built for accuracy,” achieve “79% agreement with gold-standard polysomnography” for classifying the four sleep stages, and most recently offer “95% Sleep Staging Accuracy compared to clinical sleep lab.” It argues the ring cannot measure the brain activity and eye movements that clinically define sleep stages.
What has Oura said about the lawsuit?
Oura told reporters it disputes the allegations and will defend against them, and that it stands behind its science, research and accuracy claims. According to MedCity News, the company also said its sleep-staging algorithm was built using more than 1,200 nights of data and that the ring is not a medical device or a substitute for a clinical sleep study.
Is there any money to claim from the Oura lawsuit?
No. There is no settlement, certified class or claim form. If the case settles or a class is certified, class members would be notified of any way to take part.
Sources
• Class Action Complaint — Surber v. Oura Inc., U.S. District Court for the Northern District of California, Case No. 3:26-cv-08686 (filed August 20, 2026): Complaint (PDF)• TechCrunch, “Oura faces lawsuit accusing it of misleading consumers about sleep-tracking accuracy” (August 21, 2026): TechCrunch
• MedCity News, “Why Oura’s Sleep-Tracking Lawsuit Is Really About Trust” (August 25, 2026): MedCity News
• Herberger et al., “Performance of Wearable Finger Ring Trackers for Diagnostic Sleep Measurement in the Clinical Context,” Scientific Reports (March 2025): PubMed Central
