Fitness Trackers / Withings ScanWatch Light (37mm) vs Polar Loop (2025)
Withings ScanWatch Light (37mm) vs Polar Loop (2025)
Withings ScanWatch Light (37mm)
A month of battery in a steel watch case — with no ECG, no SpO2 and no GPS chip.
Wins overall by 0.1 points
Quick Verdict
The Withings ScanWatch Light (37mm) wins by 0.1 points, which is not enough to settle it. WHOOP's format with Polar's science and no membership — but $200 and no GPS chip. Pick on the specs that matter to you, not the overall score.
The Withings ScanWatch Light (37mm) and Polar Loop (2025) are both closely matched fitness Tracker models, and the Polar Loop (2025) is $50 cheaper than the Withings ScanWatch Light (37mm) ($199.99 vs $249.95). On Battery Life, the Withings ScanWatch Light (37mm) leads (9.5 vs 6.0/10) — real endurance once continuous heart rate, SpO2 and the always-on display are enabled, not just the headline figure.. On Display & Usability, the Withings ScanWatch Light (37mm) leads (5.0 vs 2.0/10) — screen size, brightness and how much you can actually read on the wrist mid-workout.. On Subscription Freedom, the Polar Loop (2025) leads (9.5 vs 8.0/10) — the category's trap dimension: how much of what you paid for keeps working without a membership. A 10 means nothing is paywalled; a 1 means the hardware is unusable the moment you stop paying.. Overall, the Withings ScanWatch Light (37mm) scores 6.3/10 across our 8 scoring categories versus 6.2/10 for the Polar Loop (2025), though the gap is close enough that your specific use case should decide it. Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Withings ScanWatch Light (37mm) | Polar Loop (2025) |
|---|---|---|
| Price | $249.95 | $199.99 |
| Release Year | 2024 | 2025 |
| GPS | Connected GPS at best — the Amazon listing advertises 'Connected GPS' using the phone, while Withings' own shop spec sheet does not list GPS at all. Sources conflict; either way there is no GPS chip in the watch | None — no GPS chip. The Polar Flow app can use the phone's GPS when you start an outdoor session manually |
| Display | Analogue hands plus a 0.63-inch grayscale OLED sub-display (282 PPI) | None — screenless; everything is read in Polar Flow |
| Rated Battery Life ( days) | 30✓ | 8 |
| What the Battery Claim Assumes | Sources conflict: Withings' own shop page claims up to 35 days, while the Amazon listing title and launch coverage say 30 days. No SpO2 sensor is drawing power | Polar rates up to 8 days with continuous HR active; the band holds about four weeks of data if it goes unsynced |
| Subscription Model | Optional — Withings+ adds cardiologist ECG review, the AI Health Assistant, NutriCare and Readiness scoring. One month is included. Withings does not publish the Withings+ price on its US product or subscription pages | None. Polar states full access to every feature from day one with no monthly fee — the explicit anti-WHOOP position |
| Annual Subscription Cost ($) | Not published on Withings' US Withings+ page | 0 |
| Water Resistance | 5 ATM / 50 m, swimproof | WR30 — Polar rates it for bathing and swimming, a weaker rating than the 5 ATM bands here |
| ECG / AFib & FDA Status | No ECG on the Light — Withings reserves ECG and AFib detection for ScanWatch 2 and Nova. The cardiologist ECG review sold under Withings+ therefore does not apply to this model | No ECG hardware and no AFib detection |
| SpO2 Sensor | No — Withings explicitly omits the SpO2 sensor on the Light | Not listed by Polar for the Loop — the sensor package is optical HR, HRV and accelerometer |
| Phone Compatibility | iOS and Android via Withings Health Mate | iOS and Android via Polar Flow |
| Charger | Proprietary magnetic puck | Proprietary Polar Charge 2.0 USB-C cable (included) |
| Data Export | Health Mate offers a full account data export in CSV, and Withings publishes a developer API | Strongest in the screenless class — Polar Flow exports sessions as TCX/GPX, offers a full account data export and a documented AccessLink API |
| Warranty | 24 months | 24 months |
| Colors | Black & Silver, White & Rose Gold, Green, Blue | Black, Greige, Blue |
Category Scores
Tracking Accuracy
The Polar Loop (2025) leads clearly here, 8.0 against 7.0 — a 1.0-point margin on how closely steps, heart rate and sleep match reference devices — and how badly the optical sensor falls apart at high intensity.. If that is what you are buying for, the Withings ScanWatch Light (37mm) does not close the gap elsewhere.
Subscription Freedom
The Polar Loop (2025) leads clearly here, 9.5 against 8.0 — a 1.5-point margin on the category's trap dimension: how much of what you paid for keeps working without a membership. A 10 means nothing is paywalled; a 1 means the hardware is unusable the moment you stop paying.. If that is what you are buying for, the Withings ScanWatch Light (37mm) does not close the gap elsewhere.
Phone Independence
The Polar Loop (2025) leads clearly here, 2.5 against 2.0 — a 0.5-point margin on how much the device can do with the phone left at home — a real GPS chip and on-wrist readouts score high, connected-GPS screenless bands score low.. If that is what you are buying for, the Withings ScanWatch Light (37mm) does not close the gap elsewhere.
Battery Life
The Withings ScanWatch Light (37mm) leads clearly here, 9.5 against 6.0 — a 3.5-point margin on real endurance once continuous heart rate, SpO2 and the always-on display are enabled, not just the headline figure.. If that is what you are buying for, the Polar Loop (2025) does not close the gap elsewhere.
Display & Usability
The Withings ScanWatch Light (37mm) leads clearly here, 5.0 against 2.0 — a 3.0-point margin on screen size, brightness and how much you can actually read on the wrist mid-workout.. If that is what you are buying for, the Polar Loop (2025) does not close the gap elsewhere.
Health Features
The Polar Loop (2025) leads clearly here, 6.5 against 5.5 — a 1.0-point margin on depth of the health sensor suite and how much of it is FDA-cleared and enabled in the US.. If that is what you are buying for, the Withings ScanWatch Light (37mm) does not close the gap elsewhere.
App & Data Portability
The Polar Loop (2025) leads clearly here, 8.5 against 8.0 — a 0.5-point margin on quality of the companion app and whether you can get your own data out in a documented format.. If that is what you are buying for, the Withings ScanWatch Light (37mm) does not close the gap elsewhere.
Value
The Polar Loop (2025) leads clearly here, 6.5 against 5.5 — a 1.0-point margin on what the first year genuinely costs — purchase price plus any subscription needed for the advertised features.. If that is what you are buying for, the Withings ScanWatch Light (37mm) does not close the gap elsewhere.
Best For
Choose the Withings ScanWatch Light (37mm) if…
- • Battery Life matters most to you — the Withings ScanWatch Light (37mm) scores 9.5/10 here (real endurance once continuous heart rate, SpO2 and the always-on display are enabled, not just the headline figure.).
- • Display & Usability matters most to you — the Withings ScanWatch Light (37mm) scores 5.0/10 here (screen size, brightness and how much you can actually read on the wrist mid-workout.).
- • Your main use case is everyday-steps.
Choose the Polar Loop (2025) if…
- • Subscription Freedom matters most to you — the Polar Loop (2025) scores 9.5/10 here (the category's trap dimension: how much of what you paid for keeps working without a membership. A 10 means nothing is paywalled; a 1 means the hardware is unusable the moment you stop paying.).
- • Tracking Accuracy matters most to you — the Polar Loop (2025) scores 8.0/10 here (how closely steps, heart rate and sleep match reference devices — and how badly the optical sensor falls apart at high intensity.).
- • Health Features matters most to you — the Polar Loop (2025) scores 6.5/10 here (depth of the health sensor suite and how much of it is FDA-cleared and enabled in the US.).
- • You want to spend less — it's $50 cheaper.
- • Your main use case is screenless.
Pros & Cons
Withings ScanWatch Light (37mm)
Pros
- +A month or more per charge, by far the longest run time in this comparison
- +Stainless steel and real analogue hands — it passes as a watch, not a fitness band
- +CSV account export and a public API make your data genuinely portable
- +Two-year warranty and HSA/FSA eligibility
Cons
- −$249.95 buys no ECG, no SpO2 and no GPS chip — the 'Light' name is doing a lot of work
- −Sources conflict on both battery life (30 vs 35 days) and whether connected GPS is supported at all
- −The Withings+ features most people want, including cardiologist ECG review, need hardware this model does not have
- −Withings does not publish the Withings+ price on its US pages, so the real cost of ownership is unclear at purchase
- −The 0.63-inch grayscale sub-display shows very little at a glance
Polar Loop (2025)
Pros
- +Polar's sports-science pedigree — Nightly Recharge and SleepWise — with no subscription attached
- +Two band sizes in the box, so the fit problem is solved at purchase
- +Real data portability: TCX/GPX export, account export and a documented API
- +Two-year warranty, double the Fitbit and Amazfit norm
Cons
- −$199.99 for a screenless band with no GPS chip and no SpO2 — the $99.99 Amazfit Helio Strap does the same job
- −WR30 rather than 5 ATM, the weakest water rating in this comparison
- −8 days is the shortest battery life of any screenless band here
- −No ECG, no AFib detection, no FDA-cleared health feature
- −Polar Flow's interface is dated next to WHOOP's and Google Health's
Shop by Need
FAQs
Is the Withings ScanWatch Light (37mm) or Polar Loop (2025) better overall?+
Based on our 8-category scoring, the Withings ScanWatch Light (37mm) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Battery Life, the Withings ScanWatch Light (37mm) or the Polar Loop (2025)?+
The Withings ScanWatch Light (37mm) scores higher on Battery Life (9.5/10 vs 6.0/10) — real endurance once continuous heart rate, SpO2 and the always-on display are enabled, not just the headline figure..
Which is better for Display & Usability, the Withings ScanWatch Light (37mm) or the Polar Loop (2025)?+
The Withings ScanWatch Light (37mm) scores higher on Display & Usability (5.0/10 vs 2.0/10) — screen size, brightness and how much you can actually read on the wrist mid-workout..
Which is better for Subscription Freedom, the Withings ScanWatch Light (37mm) or the Polar Loop (2025)?+
The Polar Loop (2025) scores higher on Subscription Freedom (9.5/10 vs 8.0/10) — the category's trap dimension: how much of what you paid for keeps working without a membership. A 10 means nothing is paywalled; a 1 means the hardware is unusable the moment you stop paying..
Which is better for Tracking Accuracy, the Withings ScanWatch Light (37mm) or the Polar Loop (2025)?+
The Polar Loop (2025) scores higher on Tracking Accuracy (8.0/10 vs 7.0/10) — how closely steps, heart rate and sleep match reference devices — and how badly the optical sensor falls apart at high intensity..
Is the Withings ScanWatch Light (37mm) worth the price difference over the Polar Loop (2025)?+
The Polar Loop (2025) is the cheaper option at $199.99 versus $249.95. Whether the pricier model is "worth it" depends on how much you value its lead in Battery Life.
Which is better suited to my use case?+
The Withings ScanWatch Light (37mm) is the better fit if you mainly care about everyday-steps. The Polar Loop (2025) is the better fit for screenless.
What's the warranty on the Withings ScanWatch Light (37mm) vs the Polar Loop (2025)?+
The Withings ScanWatch Light (37mm) ships with a 24-month warranty; the Polar Loop (2025) ships with a 24-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
Garmin vívosmart 5 (2022) — $149.99
Premium Option
WHOOP MG (Life membership) — $359.00
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.