Circular Ring 2 Fails to Compete with Top Smart Rings Despite Unique Features

As of November 14th, 2025, the smart ring market is flooded with companies vying for the title of the best health tracker. While several high-quality products exist, the Circular Ring 2 from the French company Circular falls short of its competitors.

After testing the Circular Ring 2 for over a week, the author found that the device's software is plagued by issues. The ring takes an unusually long 14 days to get accustomed to the user's sleep, activity, and lifestyle, during which no analytics are provided. When the data finally starts syncing, it varies considerably from the Oura Ring 4 worn alongside it, and the app frequently crashes during the process.

Despite the Circular Ring 2's unique features, such as ECG and atrial fibrillation detection, blood pressure and glucose tracking, and a smart alarm that detects the lightest sleep stage, the software issues prevent the user from fully experiencing these capabilities. Many Circular Ring 2 owners have also reported similar synchronization problems, prompting the company to address the issue.

In contrast, the Oura Ring 4 remains the top choice for sleep scoring, symptom tracking, and overall health metrics. The ring's commitment to privacy and constant feature updates also make it a standout option. For those looking for a more affordable alternative, the RingConn Gen 2 Air offers similar functionality at a lower price point, though it lacks some of the advanced features of the Oura Ring 4.