Oura faces a lawsuit for supposedly deceptive sleep-tracking assertions.

      Lawsuit questions Oura’s claim of 95% accuracy in sleep staging

      Oura has cultivated its reputation on aiding users in understanding their sleep patterns. The rings provide a daily Sleep Score and estimates for light, deep, and REM sleep. However, a proposed class-action lawsuit is now casting doubt on the reliability of these figures.

      The lawsuit, filed on August 20 in the U.S. District Court for the Northern District of California, alleges that Oura misleads customers by promoting highly accurate sleep-stage tracking while actually relying on signals from the user's finger rather than directly measuring brain activity.

      Oura has previously asserted an agreement rate of 79% with the gold-standard polysomnography (PSG) when determining wakefulness, light, deep, and REM sleep. Recently, marketing claims cited in the lawsuit suggested a 95% accuracy in sleep staging compared to a clinical sleep lab.

      The lawsuit contends that such claims may create misconceptions about what the ring can genuinely measure. Clinical sleep studies evaluate factors like brain waves, eye movement, and muscle activity, whereas Oura estimates sleep stages based on heart rate, heart-rate variability, movement, skin temperature, and blood-oxygen trends in its newer models.

      The complaint also references a 2025 study published in Nature, which involved 45 patients over 45 nights and found that the Oura Ring accurately identified sleep stages only 53.18% of the time. It underestimated light sleep by 13.84 minutes and deep sleep by 5.98 minutes, while overestimating REM sleep by 31.56 minutes.

      The lawsuit was initiated by California resident Madison Surber, who purchased an Oura Ring 4 Gold for $513.68 in May 2025. She claims that Oura’s marketing led her to believe the ring would accurately track her sleep stages, stating she would either not have made the purchase or would have opted for a lower price if aware of its limitations.

      The lawsuit seeks class-action status, damages, restitution, and modifications to Oura’s advertising practices. Oura has denied the allegations, stating, “We dispute the allegations in this complaint and intend to defend against them.”

      For those who depend on the Oura Ring nightly to monitor their sleep, the significant disparity between the advertised accuracy and independent research findings raises concerns.