This is the budget-vs-reference ring question, Noise edition. The Noise Luna Ring Gen 2 is around $300 with no subscription and genuinely good sleep tracking; the Oura Ring 4 is the accuracy-and-app reference but costs $349 plus a mandatory membership. One is the own-it-outright value pick; the other is the polished experience you keep paying for.
VERDICT: TIE
Value vs reference. The Noise Luna Ring Gen 2 wins on cost — ~$300, no subscription — with accurate sleep tracking and a charging case for long total battery. The Oura Ring 4 wins on accuracy, app polish, fit range and single-charge battery, at $349 plus ~$6/month. If price and no-subscription matter most, Luna; if accuracy and experience do, Oura.
Luna: ~$300 one-time, no subscription. Oura Ring 4: $349 + ~$6/month. Over a couple of years the Luna costs far less.
Noise Luna Ring Gen 2
Accuracy
Oura is the validated reference for sleep staging and overnight HRV. The Luna is good for the price but a step behind.
Oura Ring 4
Sleep tracking
Closer than you’d expect — the Luna’s sleep staging is genuinely accurate, though Oura still leads on the finer detail.
Tie
App & ecosystem
Oura’s app is the most polished and explanatory in the category; the Luna app is capable but has some rough edges.
Oura Ring 4
Single-charge battery
Oura Ring 4: ~6–8 days. Luna: ~4 days per charge (the case extends the total). Oura lasts longer between charges.
Oura Ring 4
Fit & sizing
Oura offers a full size range with a sizing kit; the Luna’s range is narrower.
Oura Ring 4
Choose Noise Luna Ring Gen 2
Choose the Noise Luna Ring Gen 2 if you want a cheap, subscription-free ring with good sleep tracking and don’t mind leaning on the charging case.
Choose Oura Ring 4
Choose the Oura Ring 4 if you want the most accurate sleep and HRV, the best app and longer single-charge battery, and the membership is acceptable.
The short version
Budget vs reference. The Noise Luna Ring Gen 2 is ~$300 with no subscription and accurate sleep tracking; the Oura Ring 4 is the accuracy-and-app leader at $349 plus a membership.
When the Noise Luna Ring is the right pick
You want the cheaper, subscription-free ring with good sleep tracking and don’t mind the charging case.
When the Oura Ring 4 is the right pick
Accuracy, app polish, fit range and single-charge battery matter more than price, and the membership is acceptable.
Is the Noise Luna Ring a good cheap alternative to Oura?
For the price, yes — ~$300 with no subscription gets you accurate sleep tracking and core HRV. But Oura is more accurate overall, has the better app, longer single-charge battery and wider fit range. The Luna is the value pick; Oura is the reference you pay a subscription for.
How much cheaper is the Luna over time?
Substantially. The Luna is ~$300 once. The Oura Ring 4 is $349 plus ~$6/month, so after two years Oura runs roughly $490+ versus the Luna’s ~$300, with nothing further owed.
Is the Luna accurate enough?
For sleep and general recovery trends, yes — sleep staging is its strongest area. If you want the most accurate HRV and sleep data and the best app, Oura still leads, at the cost of a subscription.