These are two of the cheapest subscription-free smart rings, both aimed at people who want core Oura-style tracking without the price or the membership. The Noise Luna Ring Gen 2 (~$300) leans on a pocket charging case for a long total battery and accurate sleep; the Amazfit Helio Ring ($199) is cheaper and lighter but ships in only three sizes. Both are value picks with trade-offs.
Noise Luna Ring Gen 2 or Amazfit Helio Ring: which is better?
Practically equal by ONDA score (6.7 and 6.6)
Two budget subscription-free rings. The Amazfit Helio Ring is cheaper ($199) and lighter; the Noise Luna Ring Gen 2 (~$300) has a wider size range, a charging case for long total battery, and the same basic sleep tracking (stage estimates, not independently validated). Pick the Helio for lowest price if it fits, the Luna for better fit options and the charging-case convenience.
Noise Luna Ring Gen 2 vs Amazfit Helio Ring — head-to-head comparison by criterion
Criterion
Winner
Why
Price
Amazfit Helio Ring
Amazfit Helio: $199. Noise Luna Gen 2: ~$300. The Helio is the cheaper ring.
Subscription
Tie
Tie — both are one-time purchases with no membership.
Single-charge battery
Noise Luna Ring Gen 2
Per the manufacturers: up to 7 days for the Luna Ring (for the Gen 2, up to 5 days per Wareable) and up to 4 days for the Helio per charge. Reviewers report less in real use (Luna ~4, Helio ~2.5–3), and the Luna’s headline ~30 days depends on the charging case.
Fit & sizing
Noise Luna Ring Gen 2
The Helio ships in only three sizes (8, 10, 12); the Luna offers a wider range, so more people can fit it well.
Sleep tracking
Tie
Both offer basic sleep tracking for the price — stage estimates, with no independent validation found for either.
Extras
Noise Luna Ring Gen 2
The Luna adds a voice-activated Luna AI assistant and a pocket charging case; the Helio is more bare-bones.
Choose Noise Luna Ring Gen 2
Choose the Noise Luna Ring Gen 2 if you want basic sleep tracking (stage estimates, not independently validated), a wider size range and a charging case for long total battery, and $300 is acceptable.
Choose Amazfit Helio Ring
Choose the Amazfit Helio Ring if you want the cheapest, lightest subscription-free ring and one of its three sizes fits you.
The short version
Two budget subscription-free rings. The Amazfit Helio Ring is cheaper ($199) and lighter but limited to three sizes; the Noise Luna Ring Gen 2 (~$300) has a wider size range, a charging case for long total battery and a voice assistant.
When is the Noise Luna Ring the right pick?
You want basic sleep tracking, more fit options and the charging-case convenience, and $300 is fine.
When is the Amazfit Helio Ring the right pick?
You want the cheapest, lightest subscription-free ring and a size fits you.
Both are cheap subscription-free rings with basic sleep tracking (stage estimates, not independently validated). The Amazfit Helio is cheaper ($199) and lighter but comes in only three sizes; the Noise Luna (~$300) has a wider size range, a charging case for long total battery and a voice assistant. Pick the Helio for lowest price if it fits, the Luna for fit options and extras.
Which has better battery?
The Luna. Per the manufacturers, the Luna Ring lasts up to 7 days (for the Gen 2, up to 5 days per Wareable) and the Helio up to 4 days per charge (reviewers report about 4 and 2.5–3 days in real use), and the Luna’s pocket charging case pushes its total battery far higher, so you recharge the ring less often overall.
Will these rings fit me?
The Amazfit Helio comes in only three sizes (8, 10, 12), so it may not fit; the Noise Luna offers a wider range and is the safer bet on fit.