UPDATE: Aug. 23, 2026, 3:25 p.m. This article was updated to include a statement from Oura.
A class-action lawsuit filed in the Northern District of California alleges that the fitness tracker Oura Ring doesn't actually track one's sleep.
The complaint, filed on Aug. 20, states that Oura can't measure brain electrical activity, eye movements, muscle tone, "and other signals measured through electrodes placed on the scalp, leads on the eyes, and sensors on the chin," and because it doesn't do this, it can't track sleep or sleep cycles.
"Instead, Oura's AI models are doing guesswork as to what may be happening," it reads, "based on improper inputs, and thus taking advantage of desperate consumers who struggle with their sleep or are concerned for their health by selling faulty AI-based inference as reliable science."
While Oura states in technical materials that it doesn't track brain activity or eye movements, the lawsuit alleges that the company still claims to measure sleep stages and cycles. Clarkson Law Firm and named plaintiff Madison Surber filed the complaint. It states that around May 22, 2025, Surber bought an Oura Ring 4 Gold for $513.68 directly from Oura, and believed the ring could provide accurate data about her sleep.
The suit alleges Oura engaged in fraudulent advertising, unjust enrichment, breach of express and implied warranties, and violations of California's Unfair Competition Law, False Advertising Law, and Consumers' Legal Remedies Act. Over 100 class members seek monetary compensation totaling more than $5 million.
In a statement to Mashable via email, an Oura spokesperson wrote, "We stand behind our science, research, and accuracy claims." They also added that Oura is "committed to continuing to clearly communicate what Oura measures, what it estimates, and how members should use that information. We dispute the allegations and will defend against them in the appropriate legal forum."